2 Particle Theory of Matter Matter is made up of extremely tiny particles.These tiny particles may be molecules or ions.A model of water dioxideMolecules of the same substances are the same.A model of carbon dioxideMolecules of different substances are different.
3 Kinetic Theory of Matter Gas particles are very far apart from each other.They move at high speeds.
4 Kinetic Theory of Matter Liquid particles are much closer.They are moving continuously.
5 Kinetic Theory of Matter Solid particles are close together in a regular pattern.They cannot move from one place to another place.Solid particles are vibrating about their positions all the time.
6 ExperimentTo show that ammonia molecules and hydrochloric acid molecules are moving.Procedure1. Set up the apparatus as shown above.2. Leave the apparatus for some time and observe.
7 ExperimentTo show that ammonia molecules and hydrochloric acid molecules are moving.Result
8 To answer the questions on the next page, you must imagine that the gases are made of tiny particles
9 Ammonia solutionWhite fumeHydrochloric acidQuestionWhat happens when the hydrochloric acid particles met the ammonia particles?Form white fumeAre the particles of the two substances moving?yesDo they move at the same speed?NoIf the whole glass tube is warmed, do you think it takes a longer or shorter time for any change to be seen?It takes a shorter time to form the white fume because...Particles move faster at higher temperature
10 Ammonia solutionWhite fumeHydrochloric acidThe above experiment shows that both ammonia and hydrochloric acid diffuse.
11 Diffusion Diffusion is the spreading out of a substance. Particles of matter move from oneplace to other places.Why does diffusion occur?Is the rate of diffusion equal to the speed of moving particles?The speed of diffusion ismuch smallerCollision between the particlesslows down diffusion rate.Why?The possible path of a gas particle
12 Diffusion of bromine gas Experiment ADiffusion of bromine gasProcedure1. Place 2 drops of bromine into the gas jar and cover it immediately.2. Observe how the bromine spreads by noting the colour.gas jarcoverbromine liquidQuestion1. How far has the bromine spread?2. Can you explain how the bromine diffuses (spreads)?
13 B. Diffusion of solid in liquid Procedure1. Place a copper sulphate crystal into 75 cm3 of cold water.2. Place another piece into the same volume of hot water.3. Leave the two beaker for about 20 minutes and observe.beakerwatercopper sulphate crystal
14 B. Diffusion of solid in liquid Question1. Why did we use a coloured solid?2. Had diffusion of the coloured solid particles occurred?3.Is diffusion faster in cold water or hot water?4. Is diffusion faster in a liquid or in gas?1. We can observe the diffusion of a coloured matter.YesDiffusion is faster in hot waterDiffusion is faster in liquid
15 Change of StatesGasSolidLiquidExampleSteamIceWater
16 explained by kinetic theory Change of States:explained by kinetic theoryHeat energy is given to solid particles which then move fasterSolidLiquidHeat energy is taken away from liquid particles which then move slowerHeat energy is given to liquid particles which then move fasterLiquidGasHeat energy is taken away from gas particles which then move slower