# AP Board 9th Class Physical Science Notes Chapter 3 Is Matter Pure?

Students can go through AP State Board 9th Class Physical Science Notes Chapter 3 Is Matter Pure? to understand and remember the concept easily.

## AP State Board Syllabus 9th Class Physical Science Notes Chapter 3 Is Matter Pure?

→ In our day-to-day language, pure means something with no adulteration.

→ The mixture is made up of two or more components that are not chemically combined.

→ Mixtures are homogeneous and heterogeneous.

→ The substance is homogeneous, when its composition doesn’t change, no matter which part of the substance we take for examination.

→ A heterogeneous mixture is a mixture made up of different substances, or the same substance in different stages which are not uniformly distributed in it.

→ The solution is a homogeneous mixture of two or more substances that we cannot separate by filtration.

→ The solution has two components i.e., solvent and solute.

→ The solvent is the substance that dissolves others in it.

→ The solute is the substance, that dissolved in the solvent,

→ An amount of solute present in a saturated solution at a certain temperature is called its solubility.

→ When no more solute can be dissolved in the solution at a certain temperature, it is said to be a saturated solution.

→ If the amount of solute contained in a solution is less than the saturation level, it is called an unsaturated solution.

→ A solution is said to be dilute if the amount of solute is little and concentrate if the amount of solute is large.

→ The concentration of a solution is the amount of solute in grams presents per 100 ml or per 100 g of the solution.

→ Materials that are insoluble in a solvent and have particles that are visible to naked eyes are called suspension. A suspension is a heterogeneous mixture.

→ A mixture of two liquids that do not mix and settle into layers when they are left undisturbed is called emulsion.

→ Colloids are heterogeneous mixtures in which the particle size is too small to be seen with the naked eye, but is big enough to scatter light.

→ Colloids consist of two phases: disperse phase and dispersion medium.

→ The scattering of a beam of light is called the Tyndall effect.

→ We can use different techniques like handpicking, sieving/filtration, flotation, crystallization, chromatography, sublimation, evaporation, distillation, fractional distillation, centrifugation, etc. to separate mixtures.

→ Pure substances can be elements or compounds.

→ An element is a form of matter that cannot be broken down into simpler substances by chemical reactions.

→ A compound is a substance composed of two or more different types of elements, chemically combined in a fixed proportion.

→ Properties of compounds are different from their constituent elements, whereas mixture shows the properties of its constituting elements or compounds.

→ Pure substance: A substance is said to be pure i.e., homogeneous when the composition doesn’t change, no matter which part of the substance you take for examination.

→ Mixture: A mixture is generally made of two or more components that are not chemically combined.

→ Heterogeneous: A heterogeneous mixture is a mixture made up of different mixture substances or the same substance in different states which are not uniformly distributed in it.

→ Homogeneous: In a homogeneous mixture the components of the mixture are mixture uniformly distributed throughout it.

→ Solution: ‘The homogeneous mixture of two or more substances is that we can not separate them by the process of filtration called a solution.

→ Suspension. Materials that are insoluble in a solvent and have particles that are visible to naked eyes, form suspension. A suspension is a heterogeneous mixture.

→ Colloids: These are heterogeneous in nature and always consist of at least two types of phases and scatter a beam of visible light.

→ Colloidal dispersions: Colloids are heterogeneous mixtures in which the particle size is too small to be seen with the naked eye but big enough to scatter light.

→ Solvent: The component of the solution that dissolves the other component in it (usually the component present in larger quantity) is called the solvent.

→ Solute: The component of the solution that is dissolved in the solvent, (usually the component present in lesser quantity) is called the solute.

→ Concentration: The amount of solute present in a given amount of solution
(or)
The amount of solute dissolved in a given volume of solution is called the concentration of the solution.

→ Tyndall effect: The scattering of a beam of light is called the Tyndall effect.

→ Evaporation: Evaporation is a technique of separation of mixtures like salt and water or sugar and water, etc.

→ Centrifuge: Centrifuge ¡s a machine used to separate the mixtures like cream from milk, etc.

→ Miscible liquid: A liquid is said to be miscible if it dissolves completely in another liquid.

→ Immiscible liquid: An immiscible liquid is one that doesn’t dissolve but forms a layer over another liquid and can be separated easily.

→ Chromatography: Chromatography is a laboratory technique for the separation of mixtures into their individual components like inks and dyes.

→ Distillation: Distillation is used in the separation of components of a mixture containing two miscible liquids whose boiling points have a large difference (greater than 25°C).

→ Fractional distillation: Fractional distillation process is used to separate two or more miscible liquids when the difference in their boiling points is less than 25°C.

→ Element: An element is a basic form of matter that cannot be broken down into simpler substances by chemical reactions.

→ Compounds: Compounds are pure substances that can be separated into two or more components only by means of a chemical reaction.

→ Disperse phase: It is the substance that presents in small proportion and consists of particles of the colloidal size of mm to 100 nm.

→ Dispersion medium: It is the medium in which the colloidal particles are dispersed.

→ Emulsion: Emulsion is a mixture consisting of two liquids, that do not mix and settle into layers when they are left undisturbed.

→ Humphry Davy:

• Humphry Davy was born on 17 December 1778 and died on 29 May 1829.
• He was an English chemist and inventor.
• He discovered potassium, sodium, and boron.
• He invented the Davy lamp.