Particle Model

Question 1

What is kinetic theory?

Answer 1

• The particles of a solid vibrate slightly on the spot, or not at all.
• During heating, the particles vibrate more, in liquids and gases they vibrate faster - the particles have gained kinetic energy.
• During cooling, the particles lose their kinetic energy - liquids and gases move slower and solids become less vigorous.

Question 2

What is conduction?

Answer 2

• When particles nearest the heat source gain energy, they collid into neighbouring particles and cause them to vibrate; this repeats until all the particles are vibrating more.
• Only in solids!!

Question 3

What is convection?

Answer 3

• Only in liquids and gases!!
• Heated particles rise to the top, cooler particles are more desne because they have more energy so they sink to the bottom of the container.
• This process then repeats.

Question 4

What is evaporation?

Answer 4

• When a substance evaporates, only the particles at the top of the surface become a vapour.
• Can happen at any temperature.