9th Class Science Matter in Our Surroundings

Matter in our Surroundings

Synopsis

• Matter exists in three states, namely, in the solid, liquid and gaseous states.

• The physical properties of solids are density, specific gravity, hardness, odour, colour, point/freezing point, viscosity, solubility and heat conduction.

Particles are arranged in a regular pattern.

They are closely packed and have fixed positions.

They do not move freely but only vibrate and spin

around their fixed positions.

They are held together by strong attractive forces

and have the least amount of energy.

• The properties of liquids are surface tension, adhesion, cohesion, viscosity, buoyancy and

Vaporisation

Particles are not arranged in a regular pattern.

They are further apart and do not have fixed

positions.

They move freely and around one another.

They are held together by attractive forces which

are weaker than those in the a moderate amount of energy.

• They properties of gases are pressure, volume, temperature, kinetic energy and speed.

Particles are not arranged in a regular pattern.

They widely spaced and do not have fixed

positions.

They move freely and randomly at high speeds.

They have very weak attractive forces between

them and have the greatest amount of energy.

• Gases possess the property of intermixing with one another through diffusion.

• Heat can cause matter to change from one state to another.

• The kinetic energy of particles depends on the heat and pressure of the matter. The energy Will determine the movement of particles in the matter.

• As the state of matter of matter changes there is a transfer of energy, heat is either absorbed or released.

• Changes in the states of matter are reversible processes.