TOPIC 2 - U1 - Particle nature of matter

• Particles have energy, therefore • particles move randomly • there are spaces between the particles • there are forces between particles - Attractive forces • Repulsive forces

only play a role when particles are forced together

sub. changes directly from a solid to a gas

sub. changes directly from a gas to a solid

sub. changing from a liq to a gas

sub. changes from a solid to a liq

sub. changes from a liq to a solid

sub. changes from a gas to a liq

Spontaneous movement of particles

• Temperature - hotter the faster -Phase - liquids diffuse faster than solids • Bigger heavier particles - diffuse slower than smaller lighter particles

Erratic movement of solid particles suspended in a liquid or gas