P3 Particle model & States of matter

• Which theory attempts to explain the 3 states of matter?

  Particle (kinetic) theory
• The particle model has 3 main assumptions..

  These are?

  ~ Small

  ~ Inelastic

  ~ Spheres
• In Solids, strong attractive forces hold the particles in place, so they can only vibrate in position.

  As substance is heated, particles gain kinetic energy and vibrate faster.

  Eventually, particles have so much energy they can overcome forces holding them together and melt into a liquid.
• When a solid is heated, energy is transferred to the particles kinetic energy stores, causing them to vibrate faster.
• As heat is applied to a liquid, the particles gain kinetic energy and move faster.

  With enough energy they can break forces of attraction between the molecules.

  At this point the liquid would boil into a gas.
• When a gas is heated, particles gain kinetic energy and move faster.

  If the gas is trapped within a container that cannot expand, it means the volume of gas is fixed, so the pressure in the container increases.
• In gases,

  If the temperature is lowered, they’ll no longer be able to overcome forces, and the particles will move closer together and turn into a liquid.

  This process is called?

  Condensation
• The temperature when a solid converts into a liquid is called the melting point.

  The temperature at which a liquid converts into a gas is called the boiling point.
• Strong forces of attraction between particles..

  Solids
• Weak forces of attraction between particles..

  Liquid
• Very weak forces of attraction between particles..

  Gas
• When a gas is heated..

  ~ If it’s in an expandable container, volume will increase.

  ~ If it’s in a fixed container the pressure will increase.
• In a closed system, changes in state won’t change the mass..

  Why?

  The number of particles remain the same.
• Which state has the lowest density?

  Gases
• ‘Particles are arranged in a regular lattice structure and can only vibrate in place’

  Which state of matter is this?

  Solid
• ‘When heat is lost, particles won’t have enough energy to overcome forces of attraction, bonds start to form between particles’

  What change of state does this describe?

  Condensing