States of Matter (1a)

Unit 1, Principles of Chemistry: Part 1, a

Solid

• regular arrangement

• low kinetic energy

• vibrate in fixed positions

• strong forces of attraction

Liquid

• arranged close together

• more kinetic energy than solid particles

• move past each other

• weak forces of attraction

Gas

• arranged far apart

• a lot of kinetic energy

• move randomly in all directions

• very weak forces of attraction

Evaporation

• liquid turns into a gas

• occurs at any temperature

• faster, because it is a surface level process

Boiling

• liquid turns into a gas

• only at a certain temperature

• slower, because all the particles need to overcome forces of attraction

Diffusion

Spreading out of particles from high concentration to lower concentration until there is equal concentration throughout.

Diffusion: temperature effect

• Increases with increase in temperature

• Because when particles are heated, they gain kinetic energy and move around more

Bromine Experiment

• Lower jar: Bromine gas

• Top jar: air

• When lids are removed, bromine diffuses upwards

• Air also diffuses downwards until both jars are uniformly brown

• Hydrogen variant

  • place a lighted splint to check

  • Expected: sound from top jar because H is less dense

  • But equal sounds from both jars