1.1 Introduction to Particulate nature of matter

Element

A pure chemical substance composed of atoms with the same number of protons in the atomic nucleus

Atom

The smallest particle of an element to show the characteristic properties of that element

Compounds

A substance made by chemically combining two or more elements in a fixed ratio of atoms

Mixture

Contains more than one element or compound in no fixed ratio, which are not chemically bonded

Homogenous mixture

A mixture with uniform composition and properties throughout

Heterogenous mixture

A mixture with non-uniform composition, and its properties are not the same throughout

Filtration

The process where a solid is separated from a liquid or gas using a membrance

Distillation

Separating a solvent from a solute

• Solvent has lower boiling point than solute so it collected as a gas

Temperature

The average kinetic energy of the particles of a substance

Diffusion

The process by which the particles of a substance spread out more evenly

Sublimation

The direct inter-conversion of a solid to a gas without going through the liquid state

• Solid —→ gas

Deposition

When a gas changes directly toa soliD

• Gas ——> solid

Evaporation

When liquid changes into gas, but only at the surface and occurs below the boiling point

Boiling

When a liquid changes to gas, but at a specific temperature when the vapour pressure reaches the external atmospheric pressure