AP State Board Notes

Students can go through AP State Board 8th Class Social Studies Notes Chapter 13 The Indian Constitution to understand and remember the concept easily.

AP State Board Syllabus 8th Class Social Studies Notes Chapter 13 The Indian Constitution

→ A Constitution is a set of rules.

→ The Indian Constitution was drafted under very difficult circumstances.

→ Everyone would be equal before the law.

→ The British too had introduced some basic institutions of democratic rule in India.

→ The Constitution was drafted by an assembly of elected representatives called the Constituent Assembly.

→ We can understand our Constitution by reading the views of some of our major leaders, on our Constitution.

→ Republic means the head of the state is an elected person and not a hereditary position as in a kingdom.

→ Our Constitution does not promise equality in all respects but it seeks to ensure that all people will enjoy the same status.

→ Our country has a federal system.

→ The central government has 2 houses – Lok Sabha and Rajya Sabha.

→ Our country has a three-level democracy.

→ The Constitution also provides for some independent institutions to guard the Constitution.

→ The Constitution is a living and changing document.

→ Monarchy: Rule by a monarch

→ Representative: Typical of a class or group

→ Discrimination: Unfair treatment of different categories of people on grounds of race, sex, etc.

→ Autonomous: Self-governing

→ Constitution: A body of principles according to which a state or organization is governed

→ Sovereign: A king or queen who is the supreme ruler of a country

→ Federal system: The main social system in medieval Europe, in which a person worked for a lord in exchange for land

→ Provisional: For the present time but likely to change, temporary.

→ Draft: A preliminary version of a piece of writing

→ Republic: A state in which power is held by the people and their elected representative and which has a President rather than a king or queen

→ Secular: Not religious or spiritual

→ Fraternity: Friendship and shared support within a group

→ Amendment: A minor improvement

Students can go through AP State Board 9th Class Biology Notes Chapter 10 Soil Pollution and Functions to understand and remember the concept easily.

AP State Board Syllabus 9th Class Biology Notes Chapter 10 Soil Pollution

→ Our environment is composed of the atmosphere, earth and water.

→ The interaction of the atmosphere, lithosphere, hydrosphere and biosphere is continuing for years together.

→ Soil is one of the marvellous products of nature and without which there would be no life.

→ Soil formation is a long and complex process and it can take 100 to 10,000years to create one inch of topsoil

→ Crop quality directly depends on the quality of the agricultural soil in which it is grown.

→ The soil properties can be divided into three major categories. Physical, chemical and biological properties.

→ Soil consists of nutrients necessary for plants growth such as nitrogen, phosphorus and potassium.

→ The pH of the soil is important in determining the type of vegetation that will grow in the soil and the type of organisms that will live there.

→ Soil is the most abundant and diverse ecosystem on the earth.

→ Soil microbes convert organic forms of elements to their inorganic forms and liberate carbon dioxide, ammonia etc., by a process known as mineralization.

→ Fertility of soil is closely associated with the properties of soil and is defined by its capacity to hold water and nutrients and supply them to plants when they need them, independent of direct application of nutrients.

→ Proper soil fertility management is very important for successful crop production and farming.

→ The waste generated from various sources can be categorized into two types like biodegradable waste and non-biodegradable waste.

→ Decomposition is the process of materials being digested and broken down into simpler substances making nutrients more available to plants.

→ Soil or land pollution can be understood as the addition of substances that adversely affect the quality of soil or its fertility.

→ On the basis of sources of pollutants, soil pollution can be classified into three categories.

1. Agricultural soil pollution
2. Soil pollution by industrial effluents and solid wastes
3. Pollution due to urban activities.

→ A soil pollutant is any factor that deteriorates the quality, texture and mineral content of the soil or which disturbs the biological balance of the organisms in the soil.

→ Pesticides not only have a toxic effect on humans and animals but also decrease the fertility of the soil

→ The process of increasing the concentration of chemicals through the food chain is known as biomagnification.

→ Solid waste may be defined as the organic and inorganic waste produced by various activities of the society which have lost their value to the first user.

→ Solid waste on the basis of its sources of origin can be classified as municipal solid waste, hazardous solid waste and infectious solid waste.

→ Soil erosion occurs when the weathered soil particles are dislodged and carried away by wind or water.

→ Forests and grasslands are an excellent binding material that keeps the soil intact

→ Urban activities generate large quantities of city wastes including several biodegradable materials.

→ If solid waste is left uncollected and decomposed, they cause problems like clogging of drains, the barrier to the movement of water, foul smell, increased microbial activities etc.

→ To prevent soil pollution, we can limit construction in sensitive areas.

→ In general, we would need less fertilizer and fewer pesticides if we could all adopt the four R’s: Reduce, Reuse, Recycle and Recover.

→ Incineration of wastes is expensive and leaves a huge residue and adds to air pollution.

→ Pyrolysis is a process of combustion in absence of oxygen or the material burnt under a controlled atmosphere of oxygen.

→ Bioremediation means using a biological remedy to reduce or clean up contamination.

→ We can conserve soil by planting trees, terraces, no-till farming, contour ploughing, crop rotation, soil pH, watering the soil, salinity management, soil organisms and indigenous crops.

→ Atmosphere: The gaseous envelope surrounding the earth constitutes the atmosphere.

→ Lithosphere: Solid rocky layer covering the entire surface of the planet.

→ Hydrosphere: Contains all of the earth‘s bodies of water.

→ Biosphere: All the life-supporting zones on earth are together called the biosphere.

→ Topography: It ¡s the shape or configuration of the land represented on a map by contour lines.

→ Parent material: Any type of substance or material which undergoes some process to produce another material.

→ Weathering: Breakdown of bigger rocks into smaller mineral particles.

→ Thawing: The process whereby heat changes something from a solid to a liquid.

→ Crumb: A very small quantity of something.

→ Leaching: To be removed from soil by water passing through it.

→ Stench: A strong, very unpleasant smell.

→ Trash: Things that we throw away because we no longer want or need them.

→ Smelt: To heat and melt ore.

→ Ooze: The liquid flows from the place slowly.

→ Clog: To block or become blocked.

→ Inundate: To cover an area of land with a large amount of water.

→ Dire: Very serious.

→ Pyrolysis: It ¡s a process of combustion in absence of oxygen or the material burnt under a controlled atmosphere of oxygen.

→ Incineration: To burn substance until it is completely destroyed at high temperature.

→ Omnipresent: Present everywhere.

→ Tillage: The process of preparing and using land for growing crops.

→ Abode: Living place.

→ Gophers: Animal that lives in holes in the ground.

→ Soil fertility: The soil containing rich nutrients and is suitable for plants to grow.

→ Mineralization: It ¡s the process of converting organic forms of elements to their inorganic forms by soil microbes liberating CO₂, NH₃, sulphate, phosphate.

→ Biogeochemical cycle: The cycle that involves the flow of nutrients on earth from the environment to organisms and back through certain pathways are known as the biogeochemical cycle.

→ Biodegradable waste: Substances that can be degraded by microbes into harmless and non-toxic substances.

→ Non-biodegradable waste: Substances that cannot be easily degraded.

→ Soil erosion: Loss of top layers of soil by wind or water ¡s known as soil erosion.

→ Biomagnification: The process of increasing the concentration of toxic chemicals through the food chain.

→ Bioremediation: It means to use a biological remedy to reduce or clean up soil contamination.

→ Soil pollution: Soil pollution is defined as the build-up in soils of persistent toxic compounds, chemicals, salts, radioactive materials, or disease-causing agents, which have adverse effects on plant growth and animal health.

→ Organic soil: Soil that contains 30% or more organic matter (residues of dead plants and animals) is considered organic soil.

→ Abate: Reduce

→ Mycorrhiza: It is the symbiotic association that is taking place between a fungus and the roots of a plant.

→ Fragility: Easily broken or damaged.

→ Subtle: Not very noticeable.

→ In one acre of land where the topsoil is eight inches thick nearly five and a half tons of Bacteria are present. 50,000 Earthworms are also present in it.

→ James Hutton (1726 – 1797):
James Hutton: Father of Modern Georgy

• James Hutton was a Scottish geologist, physician, chemical manufacturer, naturalist and experimental agriculturalist
• Hutton‘s work established geology as a proper science, and thus he is often referred to as the father of modern geology.
• He recognized that the history of the earth could be determined by understanding how processes such as erosion and sedimentation work in the present day.
• He is also credited as the first scientist to publicly express the earth was alive and should be considered a superorganism.

Students can go through AP State Board 10th Class Physical Science Notes Chapter 10 Electromagnetism to understand and remember the concept easily.

AP State Board Syllabus 10th Class Physical Science Notes Chapter 10 Electromagnetism

→ Magnetic flux density (B) is defined as the ratio of flux passing through a plane perpendicular to the field and the area of the plane.

→ To find the direction of the magnetic field due to the straight conductor-carrying conductor, we use the right-hand thumb rule.

→ The current-carrying wire produces a magnetic field.

→ The magnetic induction field of the earth is approximately BH = 0.38 × 10^-4 Tesla.
Here 1 Tesla = 10⁴ Gauss.

→ F = qvB sin θ and F = ILB sin θ.

→ The magnitude of magnetic field induction at the center of the coil is always
B ∝ \(\frac{\mathrm{Ni}}{\mathrm{r}}\)
Here N = Number of turns ; i = Current; r = Radius of the coil.

→ In an electric motor, electrical energy is converted into mechanical energy.

→ Electromagnets are used to lift heavy iron pieces. They are fitted on cranes lifting heavy objects of scrap iron.

→ Faraday’s law: The induced EMF generated in a closed loop is equal to the rate of change of magnetic flux passing through it.

→ Electromagnets are used in electric bells, electric horns, telephone receivers, electric relays, microphones, radio sets, television, and loudspeakers, etc.

→ Lenz’s law: The induced current set up in the coil is in such a direction that it opposes the changes in the flux.

→ Permanent magnets are used in galvanometers, voltmeters, ammeters, speedometers, etc.

→ When a conductor of length ‘V moves perpendicular to field B with a speed v then the potential difference (voltage) developed between the ends of the conductor is B/v. This EMF is called motional EMF.

→ The polarity of electromagnets can be reversed by changing the direction of the electric current.

→ In generators, mechanical energy is converted into electrical energy.

→ The polarity of a permanent magnet cannot be reversed.

→ The effect of magnetic field on moving charges has been used to build machines, called particle accelerators. Ex: Cyclotron.

→ The electric force is collinear, whereas magnetic force is perpendicular to the magnetic field.

→ The ratio of magnetic force to electric force is very negligible.

→ In domestic circuits, the series arrangement is not used.

→ To protect electric appliances like television sets, computers, which are highly expensive, cartridge fuses are used.

→ The cost of generation of A.C is less than the cost of generation of D.C.

→ A.C can be transmitted to distant places without much loss of electric power than D.C.

→ A.C can be easily connected to D.C.

→ A.C is more dangerous than D.C.

→ In the process of electrolysis, D.C. is used.

→ If the number of turns, area, speed of the rotation of armature increases induced emf is increased.

→ An electric fuse is made of a material of low melting point.

→ Magnetic flux: The number of lines passing through the plane of area perpendicular to the field is called magnetic flux. It is denoted by ‘Φ’. Its SI unit is Weber.

→ Magnetic flux density: Magnetic flux per unit area is known as magnetic flux density. This is also known as magnetic induction.
∴ B = \(\frac{\phi}{A}\)
Unit → Weber/metre2 or Tesla

→ Electric motor: It ¡sa device which converts electrical energy into mechanical energy.

→ Slip rings: The reverse of current in an AC dynamo occurs because the two ends of the armature coil are in permanent contact with the same two slip rings and S2

→ Induced current. Whenever there ¡s a continuous change of magnetic flux linked with the closed coil, the current is generated in the coil. This is known as induced current.

→ Induced EMF: The pushing or pulling of the magnet causes a change in magnetic flux linked to the coils which cause induced EMF.

→ Electric generator: It is a device that converts mechanical energy into electrical energy.

→ DC and AC currents: An electric current whose magnitude is either constant or variable but the direction of flow in a conductor remains the same is called Direct Current. It is denoted by DC. An electric current whose magnitude changes with the time and direction reverses periodically is called Alternate Current. It is denoted by AC.

→ rms values : I_rms = \(\frac{\mathrm{I}_{0}}{\sqrt{2}}\) and V_rms = \(\frac{\mathrm{V}_{0}}{\sqrt{2}}\)
Here AC current and AC voltage are expressed in terms of RMS values. Here I and vo are the peak values of AC current and AC EMF.

→ Magnetic compass: It is a simple device to find directions. It is a small magnet that is pivoted at its center so that it can rotate in its horizontal plane, and always point towards the north-south direction of the earth, after coming to rest.

→ Ampere’s swimming rule: Imagine a swimmer along the length of the conductor in which current flows. Then the left-hand motion of the person gives the direction of deflection of the north pole of the magnetic needle placed near to it.

→ Electromagnet: An electromagnet is a temporary strong magnet and is just a solenoid with its winding on a soft iron core.

→ Permanent magnet: A permanent magnet is made from steel. As steel has more retentivity than iron, it does not lose its magnetism easily.

→ Flemmings left-hand rule: When a current-carrying wire is placed in a magnetic field, a force is exerted on the wire. According to Flemming’s rule, hold the forefinger, middle finger, and thumb of the left hand at right angles to one another, then the forefinger points in the direction of force due to the magnetic field. Middle finger points in the direction of current and the thumb points in the direction of motion of the conductor.

→ Flemming’s right-hand rule: Stretch the right hand such that forefinger, middle (Dynamo Rule) finger, and thumb are mutually perpendicular to each other. Forefinger points the direction of the field. The middle finger points the direction of the induced current. Thumb points the direction of motion of the conductor.

→ Energy meter or KWH meter: The cable connected to the energy meter records the electricity consumption of the house in kilowatt-hour.

→ Main Fuse: The live wire coming out from the output terminals or KWH meter has another fuse which is called the main fuse.

→ Electric Fuse: It is a device used in series to limit the current in an electric circuit so that it easily melts due to overheating when excessive current passes through it.

→ Armature: Armature is a coil that consists of a large number of turns of insulated copper wire wound over a soft iron core. it revolves around an axle between two poles of a strong magnet.

→ Short-circuiting: When live wire and neutral wire come in direct contact, the resistance of the wire becomes very small. Then huge current flows through the circuit and produces a large amount of heat in the circuit and the circuit catches fire. This is known as short-circuiting.

→ Michael Faraday:

1. Faraday was a British chemist and physicist who contributed significantly to the study of electromagnetism and Pedro chemistry.
2. He was born on 22 September 1791 in South London.
3. 1831 Faraday discovered electromagnetic Induction and the principle behind the electric transformer and generator.
4. As a chemist, Faraday discovered Benzene, Invented the early form of Bunsen Burner, and the system of oxidation numbers.
5. The unit of electric capacity is ‘Farad which is named after him.

→ (Hans Christian Oeited(1777 – 1851):
One of the leading scientists of the f 9th century; played a crucial role In understanding electromagnetism. He gave lectures which were quite popular among the public and also learned a lot during the tours. During one such lecture In April 1820, Oersted carried out an experiment that was never performed before. He placed a Compass needle underneath a wire and then turned on the electric current. The needle of the magnetized compass showed movement.

Oersted recognized the significance of what he had ‚ust done. Earlier, It was believed that electricity and magnetism were two dill event forces. Oersted had demonstrated that they were. Interconnected. Through this observation, he showed that electricity and magnetism Were ie1ated phenomena. Some scientists, Influenced by this experiment, continued With the modern field of “electromagnetism”. Their research resulted In several new scientific theories and various vital Inventions like the dynamo and the electric motor, Crested technologies such as the radio, television, and fiber optics. The unit of magnetic field strength Is named the Oersted In his honor. Oersted was made a foreign Academy of science in 1822.

Students can go through AP State Board 9th Class Social Studies Notes Chapter 4 Atmosphere to understand and remember the concept easily.

AP State Board Syllabus 9th Class Social Studies Notes Chapter 4 Atmosphere

→ The atmosphere is a sea of gases surrounding the earth.

→ The atmosphere consists of nitrogen (78%), oxygen (21%) and argon, neon, carbon dioxide, methane, ammonia and ozone in a very small percentage.

→ The fine dust particles or particulates can change atmospheric conditions and are beneficial to life on earth.

→ On the basis of chemical composition, the atmosphere is divided into two broad layers. They are 1) Homosphere 2) Heterosphere.

→ The Homosphere consists of three thermal layers as Troposphere, Stratosphere and Mesosphere.

→ The Heterosphere consists of two thermal layers called Thermosphere and Exosphere.

→ The gas molecules in the air constantly push each other or any other object that comes their way. This push affects them exert together on any other object is described as Air pressure.

→ When air is hot the pressure becomes low and when it is cool air pressure increases.

→ Wind flows from high-pressure areas to low-pressure areas.

→ The low-pressure belt at the earth’s surface around the equator is called the equatorial low-pressure belt or the Inter-Tropical Convergence Zone.

→ Because of the impact of Earth’s rotation on its own axis, the winds move slightly to the right in the northern hemisphere and to the left in the southern hemisphere. This effect is called the Coriolis effect

→ Depending upon the wind speed, their features, their directions, the way they occur, winds are classified into three types. They are Planetary winds, Seasonal winds and Local winds.

→ The winds that blow continuously and regularly above the world pressure belts are known as Planetary winds.

→ The winds in low latitudes that seasonally change direction between winter and summer are called Seasonal winds.

→ The winds that blow due to local variation in the temperature and pressure, and influence a very small area are called Local winds.

→ Chinook and Loo are hot and dry local winds.

→ Mistral Puna and Pampero are cold local winds.

→ Climate is a description of the average atmospheric conditions for areas over a long period of time.

→ The daily state of the atmosphere at a particular time and place is called weather.

→ Temperature, pressure, wind, humidity and precipitation are called the elements of weather.

→ The amount of water vapour in the atmosphere is called humidity.

→ The relative humidity is the ratio between the maximum water vapour that the air can hold at a given temperature and pressure and the actual amount of water vapour it holds at any given time.

→ If the atmosphere has 100% relative humidity, it is known as saturation level

→ When relative humidity exceeds 100 per cent the excess of water vapour present in the atmosphere gets condensed and forms as minute droplets of water.

→ With condensation, the droplets get heavy and fall to the ground as precipitation in the form of rain, snow, hail etc.

→ On the basis of origin, rainfall may be classified into three main types.
They are:

1. Convectional rainfall
2. Orographic rainfall and
3. Cyclonic rainfall

→ Convectional currents: The transfer of heat by the mass movement of heated particles into an area of cooler fluid.

→ Inter-Tropical Convergence Zone: The low-pressure belt around the equator is called the Equatorial low-pressure belt or the Inter-Tropical Convergence Zone.

→ Coriolis effect: Because of the impact of Earth’s rotation on its own axis the winds move slightly to the right towards the east in the northern hemisphere and to the left, i.e. towards the west in the southern hemisphere. This effect is called the Coriolis effect.

→ Relative Humidity: The amount of water vapour in the air.

→ Leeward side: The other side of the mountain receives less rainfall.

→ Tropical cyclones: Warmcore vortex circulation of tropical origin with a small diameter often of an approximately circular shape are called tropical cyclones.

→ Sleet: Wet, partly melted falling snow.

→ Chinook: The winds that move down the Rockey Mountains in the U.S.A – Canada and part of North America are known as Chinook.

→ Orographic Rainfall: The rain that occurs when the moist wind is forced to rise over mountains or other elevation in its path is called Orogenic rainfall (or) Orographic rainfall.

→ Loo: The hot and dry winds that blow in the plains of northern India from west to east in the months of May and June are called Loos.

→ Atmosphere: The thin layer of air that surrounds the earth is the atmosphere (or) The atmosphere is a sea of gases surrounding the Earth.

→ NASA: National Aeronautics and Space Administration – the space agency of the U.S.A.

→ Particulates: The fine dust particles in the atmosphere are called particulates.

→ Homosphere: The layer of the atmosphere which consists of gases like Nitrogen, Oxygen, Argon and Carbon dioxide.

→ Heterosphere: The layer which has heterogeneous composition and which is above 90 km of the atmosphere is called heterosphere.

→ Wind: The air that moves from areas of higher pressure to areas of lower pressure, is called wind.

→ Breeze: If the air that moves at a slow pace and we feel comfortable in it, is called a breeze.

→ Gust: The wind that comes in a short and fast burst is called a gust.

→ Storm: The wind that comes very fast and blows things around is called a storm.

→ Planetary winds: The winds that blow constantly, continuously, regularly above the world pressure belts are known as planetary winds.

→ Mistral: The most famous cold wind that blows from the Alps over France towards the Mediterranean sea is called Mistral.

→ Climate: The average atmospheric condition for areas over a long period of time is called the atmosphere.

→ Dew point: The critical temperature at which saturation level of humidity is reached is called a dew point.

→ Convectional Rainfall: The rainfall that occurs when moist air over the heated ground becomes warmer than the surrounding air and is forced to rise, expand, cool and yield some of its moisture, is called Convectional rainfall.

→ Cyclonic rainfall: The rainfall that is associated with the passage of a cyclone or depression is called Cyclonic rainfall.

→ Hygrometer is an instrument that measures the water vapour content (humidity) of the air.

Students can go through AP State Board 8th Class Social Studies Notes Chapter 12 Freedom Movement in Hyderabad State to understand and remember the concept easily.

AP State Board Syllabus 8th Class Social Studies Notes Chapter 12 Freedom Movement in Hyderabad State

→ Hyderabad was an important princely state of South India under British paramountcy.

→ It was ruled by the Nizams who were initially, provincial governors of the Mughal emperors.

→ Mullah Abdul Qayyum of Hyderabad became a great champion of the Congress.

→ In the year 1892 Arya Samaj was established in Hyderabad, which has credited many leaders to the nationalist movement in Hyderabad.

→ The Nizams actually discouraged the setting up of private Telugu medium schools.

→ In 1924 Madapati Hanumantha Rao and others formed the Andhra Jana Sangham.

→ The leaders of various sections decided to unite into one large organization and thus AMS was formed in 1930.

→ Later the radical elements gained leadership and a new movement of the peasants
started.

→ Enthused by the response of the youth of the state, the nationalists of Hyderabad had set up the Hyderabad State Congress in 1938.

→ in 1942 they started Satyagraha in tune with the National Quit India Movement.

→ From 1929, Ryot Sangams were established.

→ The movement was transformed in 1947-48 into a broad anti-Nizam and anti-feudal struggle demanding the merging of Hyderabad with independent India.

→ The fanatic Muslim enthusiasts formed Ittehadul Muslimeen, an organization to protect the Muslim domination of Hyderabad state and Nizam rule.

→ In 1947, the Nizam was Osman AiiKhan.

→ Hyderabad was finally integrated into Indian Union in September 1948.

→ Flrnianas: Orders issued by the rulers especially Muslim rulers

→ Vettel: Making some people work for no wages (slavery)

→ Feudal system: System of landlords

→ Subordinate kings: The kings under an emperor or a Samrat, enjoying liberty by paying some annual tribute

→ Legitimate rights: Rights that are guaranteed by law

→ Guerrilla squad: A group of armed people who attack all of a sudden

→ Jagirdars: Owners of Jagirs

→ Representative Government: A government that is run by the elected or nominated members

Students can go through AP State Board 8th Class Social Studies Notes Chapter 11B National Movement: The Last Phase 1919-1947 to understand and remember the concept easily.

AP State Board Syllabus 8th Class Social Studies Notes Chapter 11B National Movement: The Last Phase 1919-1947

→ Gandhiji arrived in India in 1915 from South Africa. He was already a respected leader known internationally.

→ His earliest interventions were in local movements in Champaran and Kheda.

→ He did not associate with any Congress faction. He built his own political program and space in nationalist politics.

→ Muslim League was formed in 1906 and Hindu Mahasabha in 1915.

→ During Rowlatt Satyagraha the participants tried to ensure that Hindus and Muslims were united in the fight against British rule.

→ The Non-Cooperation Movement gained momentum through 1921-22.

→ Guntur District was at the center of nationalist activity and the participation was very widespread.

→ Sometimes people thought of Gandhiji as someone who could help them overcome their misery and poverty.

→ On March 13th, 1930 Gandhiji led his March to Dandi village to break the government salt laws. A wave of enthusiasm swept the country.

→ The combined struggles of the Indian people bore fruit when the Government of India Act of 1935 prescribed provincial autonomy.

→ Subhash Chandra Bose organized the Indian National Army (INA) with the cooperation of Rash Bihari Bose in Burma and Andamans.

→ The period after 1940 was characterized by intensive activities of radical organizations.

→ Louis Mountbatten, who was appointed Viceroy in early 1947 was not able to resolve the differences between the Muslim League and the Congress party.

→ Independence is our strength. Partition is our failure.

→ Nationalism: Patriotic feeling often to an extensive degree

→ Secular: Not religious or spiritual

→ Terrorist: A person who uses violence and intimidation in the attempt to achieve political aims unofficially

→ extremism: Holding extreme political or religious views

→ Satyagraha: True anger. It was introduced and led by Gandhiji in our Independence movement.

→ Non-Cooperation: Not rendering co-operation to the government by not accepting their policies, not obeying their orders, and not paying taxes, etc.

→ Civil Disobedience: Refuse to be obedient by the people of a nation

→ Subcontinent: The land or a country that has all the characteristics of a continent

Students can go through AP State Board 10th Class Physical Science Notes Chapter 9 Electric Current to understand and remember the concept easily.

AP State Board Syllabus 10th Class Physical Science Notes Chapter 9 Electric Current

→ A negative charge flows through an electric wire when it is connected to an electric circuit.

→ Lightning is an electric discharge between two clouds or between clouds and the earth. This is an example of the motion of charge in the atmosphere.

→ In a circuit, the battery stores chemical energy, and this energy converts into electric energy.

→ The material which transfers energy from the battery (source) to the bulb (consumer) is called a conductor.

→ Electric charge (I) = \(\frac{\text { Electric charge (Q) }}{\text { Time interval (t) }}\)

→ The SI unit of the electric current is ampere (A).

→ 1 Ampere = \(\frac{1 \text { coulomb }}{1 \text { second }}\)

→ The electrons in the conductor move with a constant average speed called drift speed or drift velocity.

→ The charge carriers in a conductor are electrons. The magnitude of the electric charge is 1.602 × 10^-19 C.

→ The electron density of copper is 8.5 × 10²⁸ m^-3.

→ The direction of the electric current is the direct flow of positive charges.

→ An ammeter is used to measure electric current. It is always connected in series to the circuit. Work done by the electric force on the unit positive charge to move it through a distance is called the potential difference. It is denoted by V.

→ V = \(\frac{W}{q}=\frac{\text { Workdone }}{\text { Charge }}=\frac{\text { Joule }}{\text { Coulomb }}\)

→ Potential difference is also called voltage. The SI unit of potential difference is volt (V).

→ The amount of charge accumulated on the plates depends on the nature of the chemical used in the battery.

→ The direction of the electric field is from positive terminal to negative terminal in the conductor.

→ Electromotive force (emf) is defined as the work done by the chemical force to move unit positive charge from negative terminal to positive terminal of the battery.

→ A voltmeter is used to measure potential difference or emf across an electric device like a battery.

→ \(\frac{\mathrm{V}}{\mathrm{I}}\) is constant. This constant is called the resistance of the conductor.

→ According to Ohm’s law, the potential difference between the ends of a conductor is directly proportional to the electric current passing through it at a constant temperature.

→ The SI unit of resistance is Ohm (Ω).

→ 1 Ohm = \(\frac{1 \text { Volt }}{1 \text { Ampere }}\)

→ Based on Ohm’s law materials are classified into two categories. They are ohmic conductors and non-ohmic conductors.

→ Metals obey Ohm’s law. They are called ohmic conductors.

→ LEDs are non-ohmic conductors. They don’t obey Ohm’s law.

→ Ohm’s law is not applicable to gaseous conductors and semi-conductors.

→ The resistance of a conductor is defined as the obstruction to the motion of the electrons in a conductor.

→ The material which offers resistance to the motion of electrons is called a resistor.

→ The resistance of the human body generally varies from 100 Ω (if the body is wet with salt water) to 5,00,000 Ω (if the skin is very dry).

→ The electric shock is a combined effect of potential difference, electric current, and resistance of the human body.

→ Temperature, nature of the material, length of the conductor, and cross-section area are the factors that affect resistance.

→ R = \(\frac{\rho l}{A}\) (p = density, l = length of the conductor, A = the cross-section area)

→ The filament of an electric bulb is made of tungsten.

→ The melting point of tungsten is 3422° C.

→ Semiconductors are used to make diodes, transistors, and integrated circuits.

→ A closed path created by the connecting wires through a battery along which the electrons conductor is called a circuit.

→ If the current drawn by a resistor is equal to the current drawn by the combination of resistors, then the resistor is called an equivalent resistor.

→ Two or more resistors are said to be connected in series if the same current flows through them.

→ Two or more resistors are said to be connected in parallel if the same potential difference exists across them.

→ According to Kirchhoff,
“At any junction point in a circuit where the current can divide, the sum of the currents into the junction must equal the sum of the currents leaving the junction.” This law is called the junction law.

→ According to Kirchhoff,
“The algebraic sum of the increases and decreases in potential difference across various components of a closed circuit loop must be zero.”

→ Electric power = V × I = voltage × current (I).

→ SI unit of power is the watt.

→ Electrical energy is the product of power and time.
E = power × time

→ Units of electrical energy are W and KWH (unit).

→ Charge: Positive or negative particles present in an electric circuit.

→ Potential difference: Work done by the electric force on the unit positive charge to move it through a distance.

→ Electric current: The ordered motion of electrons. (OR) The amount of charge crossing any cross-section of the conductor in one second.

→ Multi-meter: It is an electronic measuring instrument that combines several measurement functions in one unit.

→ Ohm’s law: V = IR; The potential difference between the ends of a conductor is directly proportional to the electric current passing through it at a constant temperature.

→ Resistance: The obstruction to the motion of the electrons in a conductor.

→ Resistivity (ρ): Resistance offered by a conductor having unit length and unit cross-section area. (constant in R = \(\frac{\rho l}{A}\))

→ Kirchhoff’s laws: Two simple rules of Kirchhoff applicable to any DC circuit containing batteries and resistors connected in any way.

→ Electric power: The product of voltage and current.

→ Electric energy: The product of electric power and time.

→ Conductivity (σ): The reciprocal of resistivity.

→ Resistor: The material which offers resistance to the motion of electrons.

→ Overloading (or): When the current drawn from the mains is more than 20 A, Short circuit overheating occurs and may cause a fire. This is called overloading.

→ Fuse: The fuse consists of a thin wire of a low melting point.

→ Semi-conductors: The materials whose resistivity is 10⁵ to 10¹⁰ times more than that of metals and 10¹⁵ to 10¹⁶ times less than that of insulators.
Eg: Silicon, Germanium.

→ Conductors: The materials which can conduct electricity.

→ Insulators: The materials which can’t conduct electricity.

→ Sir Charles Wheatstone(1802 – 1875):

• Sir Charles Wheatstone was a professor in London. He was very famous for his telegraph and stereoscope.
• He discovered the principles of stereoscopic vision and invented the stereoscope.
• His name is attached to the circuit he invented for the newly invented telegraph.

Students can go through AP State Board 9th Class Biology Notes Chapter 8 Challenges in Improving Agricultural Products to understand and remember the concept easily.

AP State Board Syllabus 9th Class Biology Notes Chapter 8 Challenges in Improving Agricultural Products

→ Increasing food production in proportion to the increasing population is a big challenge for our country.

→ The production of a crop depends on

• the kind of seeds planted,
• the properties of the soil,
• the availability and proper application of irrigation and fertilizers,
• the weather, controlling insect attacks,
• the growth of weeds and so on.

→ Alternating crops preserve soil fertility.

→ Producing a variety of crops, as well as an increase in production, can be possible in a mixed crop system.

→ Irrigation plays an important role in increasing crop production.

→ A plant uses only 0.1 per cent of the water it absorbs to form carbohydrates.

→ Only the nutrient that dissolves in water is absorbed by the roots of the plant

→ Hybridization methods and genetic engineering methods enables us to bring desirable characters in seeds.

→ Transpiration and absorption of water occur through stomata.

→ Macronutrients are required in large quantities by plants. e.g.: Nitrogen, Phosphorous and Potassium.

→ Micronutrients are required in small quantities by plants. e.g.: Iron, Boran, Manganese, Zinc etc.

→ Agriculture officers advise farmers to cultivate dryland crops in fewer water areas.

→ Leguminous plants with root nodules supply nitrogen to the plant

→ Organic manure is produced by decaying plant and animal wastes.

→ Nutrients are replenished with crop rotation, adding organic manure or chemical fertilizers.

→ Green manure crops are grown so that they can be ploughed back into the soil

→ Biofertilizers synthesise nutrients from the environment or from soil to plants.

→ Green leaf manure can be prepared by using any plant leaves.

→ Soil testing centres give us knowledge about the soil

→ In organic farming, farmers use natural manures and natural pest-controlling methods.

→ Humus and water holding capacity are increased in the soil by applying natural manure.

→ Friendly insects control harmful insects.

→ Over usage of insecticides, fungicides, weedicides, pesticides lead to soil pollution, water pollution and hazardous to biodiversity.

→ Food Chain: Describes the linear sequence of organisms which represent their prey-predator relationship in the ecosystem.

→ Ecology: It ¡s the scientific study ¡n which plants, animals and people are related to each other and the environment.

→ Irrigation: To supply land or crops with water.

→ Kharif Crop: Crop refers to the planting, cultivation and harvesting of any domesticated plant sown in the rainy (monsoon) season.
E.g.: Paddy, Sugarcane, Maize etc.

→ Mixed Crops: Cultivation of more than one crop in the same field.

→ Rabi Crop: Agricultural crops sown in winter and harvested in the summer season. E.g.: Wheat, barley, sesame etc.

→ Fertilizers: Substance that ¡s applied to increase soil fertility and plant growth. May be organic or inorganic.

→ Macronutrients: Nutrients required ¡n large quantities by plants.
E.g.: Nitrogen, Phosphorous and Potassium.

→ Micronutrients: Nutrients required in small quantities by plants.
E.g.: Iron, Manganese, Boron, Zinc, Copper, Molybdenum etc.

→ Crop rotation: It is the process ¡n which one crop is followed by another crop on an agricultural field.
E.g.: After cultivation of Paddy, Black gram or Groundnut has to be grown followed by paddy again.

→ Replenish: To fill something again put new supplies into something. Soil testing centre: Tests the soil and give us knowledge about the soil.

→ Soil testing centre: Tests the soil and give us knowledge about the soil.

→ Synthetic pyrethroids: Chemicals used to control pests on crops.
E. g.: Pesticides, insecticides.

→ Biofertilizers: Fertilizers synthesized by microorganisms from the environment or from soil to plants.

→ Indigenous: Native, not foreign.

→ Insecticides: Chemicals used to kill insects.

→ Fungicides: Chemicals used to kill fungi.

→ Weedicides: Chemicals used to kill weeds.

→ Herbicides: Chemicals used to kill herbs.

→ Predatory insects: Insects that kill and eat insects.

→ Bacteria: Unicellular microorganisms reproduce by binary fission.

→ Immunity: Resistance developed against chemicals or things or animals. Stomata: Microscopic holes present in the epidermis of the leaf, helps in transpiration.

→ Carbohydrate: It ¡s an organic compound that consists only of carbon, hydrogen and oxygen. A major food source.

→ Bacterial culture: the initial step in studying morphology and identification of bacteria ¡n the disease process.

→ Mixed Crops: More than one crop ¡s cultivated ¡n the same field.

→ Organic farming: In this type of farming farmers use natural manures and natural pest-controlling methods. Crop rotation, mixed crops are also practised.

→ Vermicompost: It is the product or process of composting using worms usually earthworms.

→ Ingredients: A component part, constituent.

→ Watershed: A ridge of land that separates two adjacent river systems. A watershed is a basin-like landform defined by high points and ridgelines that descend into lower elevations and stream valleys.

→ Weeds: Other plants grow in afield along with the crop. These plants are called weeds.

→ Irrigated farming: Supplying water to land or crops is called irrigated farming.

→ Unirrigated farming: A farming that does not supply water to land or crops is called unirrigated forming.

→ Dr M.S.Swaminathan 7th August 1924:

• Dr M.S.Swaminathan is an Indian scientist doing his research in the agricultural industry.
• He is known as the fat her of the Green Revolution in India.
• He had contributed to the development high yielding varieties of wheat in India.
• From 1972 to 1979 he was director-general of the Indian Council of Agricultural Research (ICAR) and was the minister of Agriculture from 1979 to 1980.
• He served as director-general of the International Rice Research Institute (1982-88) at Manila.
• He is the founder and chairman of the M.S. Swaminathan Research Foundation and striving to rid the world of hunger and poverty.

Students can go through AP State Board 8th Class Social Studies Notes Chapter 11A National Movement: The Early Phase 1885-1919 to understand and remember the concept easily.

AP State Board Syllabus 8th Class Social Studies Notes Chapter 11A National Movement: The Early Phase 1885-1919

→ The National Movement in India forms an important epoch in history.

→ With the growth of English education during the late nineteenth century in some major cities, a new consciousness began to develop.

→ In 1866, Dadabhai Naoroji organized the “East India Association” in London to discuss the Indian question.

→ All the provincial nationalistic intellectuals came together in the first session of the Indian National Congress at Bombay in December 1885.

→ Moderates adopted a policy of pray, petition, and protest.

→ With the start of the Swadeshi movement around 1903, the Indian National Congress movement took a major leap forward.

→ The Swadeshi movement gave tremendous impetus to Indian history, particularly the textile industry of India.

→ Bal Gangadhar Tilak gave the famous slogan, “Swaraj is my birthright and I shall have it.”

→ There was a split in the Congress in the 1907 Surat session.

→ Tilak joined his hands with Annie Besant to launch a movement for ‘Home Rule’.

→ The two factions of the Congress united again in 1916 through the Lucknow pact.

→ Mahatma Gandhi came back from South Africa and joined the Indian freedom movement.

→ Sovereign: Having authority on self (on a country or a person or a race)

→ Racial discrimination: The discrimination showed by the Europeans especially the British towards other races. e.g.: Blacks & Whites.

→ Resolution: A decision which is taken in a meeting or self.

→ Moderates: The freedom fighters who followed a policy of petition, pray, and protest.

→ Petitions: Requisitions to the government or higher authorities to fulfill some wants

→ Swadeshi: Which are not belonged to foreign

→ Boycott: Refuse to deal with a person, organization, or country as punishment or a protest.

→ Picketing: A group of people positioned outside a workplace with the aim of persuading other people not to work during a strike.

→ Swaraj: Full-fledged freedom

→ Protest: Show disagreement

→ Extremism: A policy followed by some freedom fighters like Tilak etc., to achieve freedom in extreme ways.

Students can go through AP State Board 8th Class Social Studies Notes Chapter 10 Landlords and Tenants under the British and the Nizam to understand and remember the concept easily.

AP State Board Syllabus 8th Class Social Studies Notes Chapter 10 Landlords and Tenants under the British and the Nizam

→ During the time of the Mughal emperors, on their behalf them, the zamindars collected land revenue from the peasants.

→ Khudkhasht lands are lands of zamindars on which the laborers worked.

→ The English East India Company introduced the Permanent Settlement in 1793 when Cornwallis was the Governor-General.

→ By 1820, the prices of grains in the market rose and cultivation slowly expanded.

→ The zamindars did not have an interest in improving the land.

→ Nizam handed over Rayalaseema to the British on account of debt.

→ Some British administrators believed that it was the duty of the government to invest in large-scale irrigation works.

→ Even in the Ryotwari areas, the land revenue was fixed at a very high level.

→ Peasants very often borrowed money from moneylenders in order to pay their land revenue.

→ During the colonial period, the peasants were forced to do ‘Vetti’ on the personal land of the landlords.

→ The zamindars also tried to extract as much money as they could from the peasants under a variety of pretexts.

→ In the Hyderabad State under the Nizam rule, there were many forms of subordinate chieftaincies.

→ The large landlords were called Doras.

→ Famines or massive food shortages leading to acute distress were a regular feature of British rule. Not less than 11 famines occurred during the latter half of the 19th century.

→ The famous peasant movements were the Deccan riots of the 1860s, Rampa features, and Mappila agitations.

→ Landlords: Zamindars gave their land to peasants either for a share of the products or for a fixed rent. These peasants were called Landlords.

→ Moneylenders: Persons who lend money on interest to the needy (on the mortgage)

→ Jagirs: These are the areas of Jagirdars, Subordinate Chieftaincies in the Hyderabad State under Nizam rule.

→ Santhanam: Some areas were ruled by Swadeshi rulers under British rule.

→ Inamdar’s: The people who received ‘Inams’ from Nizam in the form of land.
→ Patta: A paper order which declares the ownership of land.

→ Ryotwari: Ryotwari means peasant tenure.

→ Deshmukh: The person who collects revenue in Hyderabad State during Nizam’s rule.

Students can go through AP State Board 9th Class Biology Notes Chapter 7 Animal Behaviour to understand and remember the concept easily.

AP State Board Syllabus 9th Class Biology Notes Chapter 7 Animal Behaviour

→ Animal behaviour is influenced by many factors.

→ Animal behaviour is the scientific study of the wild and wonderful ways in which animals interact with each other, with other living beings, and with the environment

→ Both external and internal stimuli prompt behaviours.

→ Animal behaviour is studied as instinct, imprinting, conditioning and imitation.

→ Instinctual behaviours are inborn behaviours that need not be learned.

→ Making nests by birds, choose mates and forming groups for protection etc., are examples of instinctive behaviour.

→ Chickens and ducklings recognise their mother because of a behaviour type called imprinting.

→ Conditioning is a type of behaviour involving a response to a stimulus that is different from the natural one.

→ Ivan Pavlov conducted experiments on conditioning.

→ Imitation is a type of behaviour where one animal copies another animal.

→ Human behaviour is more complex because we are more intelligent and aware of ourselves.

→ Tagging help scientists follow the journeys the animals make.

→ Identifying or smelling the ability of dogs and searching and communicating the nature of ants is because of pheromones.

→ Beaver, a mammal, which lives in North America builds dams across water streams,

→ Dolphins have great logical thinking power.

→ In 1977 Ervin Pepperberg made learned more than 100 words to Alex, the grey parrot

→ Some animals spray bad smells through their body to protect from predators. e.g.:Tasmanian devil.

→ The scientific study of animal behaviour is called Ethology.

→ Instinct: This type of behaviour need not be learned. They are present from birth.

→ Reflex: These are also a type of instinctive behaviour. We do not have to learn this.

→ Imprinting: It is a type of behaviour. Recognition of mother by chickens and ducklings after they are hatched from the eggs.

→ Conditioning: It ¡s a type of behaviour involving a response to a stimulus that is different from the natural one. It ¡s a type of learned behaviour.

→ limitation: It ¡s a type of behaviour where one animal copies another animal.

→ Creativity: Make a new thing.

→ Ethology: It is the scientific and objective study of animal behaviour.

→ Primates: The group of mammals that includes humans and monkeys.

→ Konrad Lorenz (1903 to 1989) was an Austrian scientist who studied animal behaviour. He discovered that if he reared geese (give the local name of this) since they hatched; they became imprinted on him. They followed him around and preferred to be near him even when they had grown into adult geese.

→ Some animals spray bad smells through their body to protect from predators. The Tasmanian Devil is the worst smelling animal in the animal kingdom. We are also familiar with a beetle with a foul smell called Bombardier Beetle.

It has two chemicals hydroquinone and hydrogen peroxide stored in its body. Whenever the beetle feels threatened, these chemicals mix with some special enzymes and that heat up the liquids, which gives out a bad smell from its body.

→ Konrad Lorenz (1903 – 1989):

• Konrad Lorenz was an Austrian zoologist, ethologist and ornithologist
• He is often regarded as one of the founders of modern ethology.
• He discovered that if he reared geese since they hatch they became imprinted on him.
• They followed him around and preferred to be near him even when they had grown into adult geese.
• Konrad Lorenzsha red the 1973 Nobel Prize in Physiology or Medicine with Nikolas Tin bergen and Ka rl von Frisch.

Students can go through AP State Board 10th Class Physical Science Notes Chapter 8 Chemical Bonding to understand and remember the concept easily.

AP State Board Syllabus 10th Class Physical Science Notes Chapter 8 Chemical Bonding

→ A chemical bond is an attractive force between two atoms in a molecule.

→ Atoms which contain 8 electrons in the outermost shell are stable and less reactive.

→ Electron transfer occurs from one atom to another because atoms try to acquire an inert gas configuration.

→ Ions are charged particles.

→ The atom which loses electron acquire positive charge and the atoms gain electrons acquire a negative charge.

→ The formation of ionic compounds involves the formation of ions and the attraction of ion pairs.

→ Oxidation involves the removal of electrons.

→ Reduction involves the addition of electrons.

→ Oxidation and reduction go side by side.

→ The compounds containing molecules that are formed by sharing of electrons are known as covalent compounds.

→ Covalent compounds are soft with low melting and boiling points.

→ Molecules having two oppositely charged poles are called polar molecules.

→ Vander Waal’s forces are purely electrostatic forces operating between molecules at a short distance.

→ A dipolar molecule attracting announcer dipolar molecule is called dipole-dipole attraction.

→ A strong bond is formed by the maximum overlap of orbitals.

→ End-end overlap of orbitals leads to the formation of sigma (σ) bond and part overlap of orbitals leads to the formation of pi (π) bond.

→ a bond is stronger than an π bond.

→ σ (Sigma) bond exists independently.

→ π bond has no independent existence. It exists only in the presence of a sigma bond.

→ In a double bond one, a and one π bond are present.

→ In a triple bond, one d and two π bonds are present.

→ s – s overlap is present in H₂.

→ p – p overlap is present in F₂, Cl₂, Br_2, and I₂.

→ s – p overlap is present in HF, HC/, HBr, and HI.

→ Molecules having single bonds have only o bonds.

→ Molecules having a single bond are H₂, F₂, Cl₂, Br₂, I₂, BeCl₂, etc.

→ Molecules having double bonds are O₂, C₂H₄, CO₂, etc.

→ C₂H₂, IM₂, HCN, CaC₂, etc. have triple bonds.

→ The number of valence electrons available in the atoms decides the type of bond.

→ To explain the bond angles in the molecules through covalent bonds the Valence – Shell – Electron – Pair – Repulsion – Theory (VSEPR).

→ VSEPR was proposed by Sidgwickand Powell (1940). It was further improved by Gillespie and Nyholm (1957).

→ Electrons: Elementary particles in an atom with a negative charge.

→ Noble gases: A group of monoatomic gaseous elements forming group ‘O’ of the periodic table.

→ Lewis dot structure: The valence electrons in the atom of an element are depicted in a short form by Lewis symbol or Lewis dot structure.

→ Octet rule: A stable group of eight electrons in the outer shell of an atom is called the octet rule.

→ Chemical bond: The force of attraction between any two atoms or a group of atoms that results in a stable entity is called a chemical bond.

→ Ionic bond: The electrostatic attraction force that keeps cation and anion together to form a new electrically neutral compound is called ‘Ionic bond’.

→ Covalent bond: The chemical bond formed between two atoms by mutual sharing of a pair of valence shell electrons so that both of them can attain octet or duplet in their valence shell is called the covalent bond.

→ Cation: It is a positively charged ion formed by the removal of an electron from an atom.

→ Anion: It is a negatively charged ion formed by the addition of an electron to the atom.

→ Electrostatic force: Force of attraction between positively charged and negatively charged bodies or ions is called electrostatic force.

→ Electrovalent: The valence concept has been explained in terms of electrons. It is also called electrovalent.

→ Polar solvent: Polar solvents are the compounds such as water and liquid ammonia which have dipole moments and consequently high dielectric constants. The solvents are capable of dissolving ionic compounds or covalent compounds that ionize.

→ Non-polar solvent: Non-polar solvents are compounds such ethane and benzene, which do not have dipole moments. These do not dissolve in but will dissolve nonpolar covalent compounds

→ Formation of molecules: Atoms combine and form molecules. This is called the formation of molecules.

→ Ionic compounds: The compounds formed by the ionic bonds are called compounds.

→ Covalent compounds: The compounds formed by the covalent bonds are covalent compounds.

→ Electropositive character: The ability to lose electrons and become a positively charged ion of an atom is called the electropositive character.

→ Electronegative character: The tendency of an atom to gain electrons and become a negative ion.

→ Polar bonds: These are formed due to unequal sharing of electrons by the combining atoms.

→ Bonded pair of electrons: Electrons which arranged by atoms to share and form a bond is called bonded pair of electrons.

→ Lone pair: Unshared electron pair or non-bonding electron pair.

→ Bond length: Bond length or bond distance is the equilibrium distance between the nuclei of two atoms that form a covalent bond.

→ Bond energy: An amount of energy associated with a bond in a chemical compound.

→ The shape of the molecules: While atoms combine and form molecules they should have some shape. They are called the shape of the molecules.

→ Linear: A molecule in which the atoms are in a straight line as in carbon dioxide O = C = O.

→ Tetrahedral: Having four faces.

→ Properties of Ionic and: Formula mass, physical appearance, type of bond, covalent compounds melting point, boiling point, solubility, etc.

→ Configuration: The arrangement of electrons around the nudes in an atom.

→ Oxidation: The process in which an atom, ion, or molecule loses electrons.

→ Conductivity: Covalent compounds are poor conductors of electricity due to rigid bonding.

→ Van der Waal forces: Van der Waal forces are purely electrostatic forces operating between molecules at a short distance.

→ Dipole – dIpole forces: A dipolar molecule attracting another dipolar molecule.

→ Banana bond: Informal name for the type of electron-deficient bond holding the B – H – B bridges in boranes and similar compounds.

→ Bivalent or divalent: Having a valency of two.

→ Bisulfate: Hydrogen sulfate.

→ Alkali: A base that dissolves in water to give hydroxide ions.

→ Atom: The smallest part of an element that can exist chemically.

→ Single bond: Covalent bonds in which one pair of electrons is shared are known as covalent ‘single bond’.

→ Double bond: Covalent bonds in which two pairs of electrons are shared are known as covalent ‘double bonds’.

→ Triple bond: Covalent bonds in which three pairs of electrons are shared are known as covalent ‘triple bonds’.

→ Compound: A substance formed by the combination of elements in fixed proportions.

→ Dissociation: The breakdown of a molecule, ion, etc. into smaller molecules, ions, etc.

→ Electronegativity: It is the ability of the bonded atom to attract the electron density of the shared electrons.

→ Count Alessandro Volta (1745 – 1827):

• Volta was born in Como, Italy to a noble family.
• He made discoveries In electrostatic, meteorology, and pneumatics.
• His most famous invention, however, is the first battery (cell).
• Volta’s battery was later refined by other scientists and the French emperor, Nepolean, made volta a TMCount” for his discovery.