Kinetic Particle Theory Revision

What is Kinetic Particle Theory?

• All matter are made up of particles– Particles: atoms, molecules and ions

• The properties of different matters are determined by the arrangement and movement of particles.– Kinetic Particle Theory

• Describes the arrangement and movement of the particles.

Properties at Particle Level

Solid Liquid Gas

Forces of attraction

Strongest Strong Weakest

Motion of particles

Vibrate in fixed position

Slide over each other

Move freely at great speeds

Kinetic energy Lowest low Highest

Arrangement Orderly

Closely packed

Disorderly

Packed

Disorderly

Very far apart

Affects motion and arrangement of particles

Affects volume and compressibility– fixed or not

Affects shape – fixed or not

Effects of heat on particles and temperature

• As matter is heated, the particles gain kinetic energy (move/vibrate faster)

• When temperature reaches melting/boiling point, heat energy is used to overcome the forces of attraction.

• When all the particles have overcame the forces of attraction, heat energy increase the kinetic energy of particles.

• Temperature rises

• Temperature remains constant

• Temperature rises

Particles Temperature

Effects of cooling on particles and temperature

• As matter is cooled, the particles lose kinetic energy (move/vibrate slower)

• When temperature reaches melting/boiling point, particles are attracted together and release heat energy to the surroundings.

• When all the particles have overcame the forces of attraction, the particles continue to lose kinetic energy

• Temperature decreases

• Temperature remains constant

• Temperature decreases

Particles Temperature

Regarding the assignment

MCQ

• C

• No possible answer; The answer should be processes 2,3 and 5

• C; The individual ions will separate far apart.

Regarding the assignment

• Question 4a:– A lot of you just stated what are particles in

liquid and gas are like but did not directly compare the differences

– Example of one difference• Particles in liquid are packed closer to each other

than particles in gas; or

• Particles in liquid are packed while particles in gas are far apart

Regarding the assignment

• Question 4b:– A lot of you just stated what happens to the particles

when the liquid is boiling but did not mention what happens before and after boiling.

• From 25oC to 100oC, the particles gain kinetic energy and move faster. When temperature rises to 100oC, heat energy is used to overcome the attractive forces between the particles and the particles move further apart. From 100oC to 150oC, all the particles have separated further apart and are moving faster as the temperature rises.