Topic 1: Particles and Simple Calculations

Question 1

What are the distinguishing properties of a solid

Answer 1

Maintain their shape as they’re held in fixed positions by strong attractive forces. Forces partially overcome heat when solid melts. Cannot be compressed as little space between particles.

Question 2

What are the distinguishing properties of a liquid

Answer 2

Have fixed volume, changes shape to fill container as particles are mobile but held together by weak forces. Forces fully overcome by heat when liquid vaporises.
Can be compressed slightly as some space between particles.

Question 3

What are the distinguishing properties of a gas

Answer 3

Don’t have fixed volume (at certain temp). Expands to fill space available. Particles move rapidly and randomly in all directions with no attractive forces. Can be compressed a lot as lots of space between particles.

Question 4

Describe the structure of solids in terms of particle separation, arrangement and types of motion.

Answer 4

Made up of particles in fixed positions within organised structure called a lattice. Particles don’t swap positions.

Question 5

Describe the structure of liquids

Answer 5

Made up of particles moving about in disordered arrangement. Particles can swap positions by moving past each other.

Question 6

Describe the structure of gases

Answer 6

Made up of particles moving about rapidly in all directions. Particles collide with side of container which causes pressure.

Question 7

Phase transition of solid to liquid

Answer 7

Melting

Question 8

Phase transition of liquid to gas

Answer 8

Boiling

Question 9

Phase transition of solid directly to gas

Answer 9

Subliming

Question 10

Phase transition of gas to liquid

Answer 10

Condensing

Question 11

Phase transition of liquid to solid

Answer 11

Solidifying

Question 12

Phase transition of gas directly to solid

Answer 12

Reverse subliming

Question 13

Boiling Point

Answer 13

The temperature at which a substance boils

Question 14

Melting Point

Answer 14

The temperature at which a substance melts

Question 15

In what condition is a substance a solid in room temperature?

Answer 15

If the room temperature is below its melting point e.g wax

Question 16

In what condition is a substance a liquid in room temperature?

Answer 16

If room temperature is above its melting point and below its boiling point e.g water

Question 17

In what condition is a substance a gas in room temperature?

Answer 17

If room temperature is above both its melting and boiling point e.g nitrogen, oxygen

Question 18

What is temperature? (a measure of)

Answer 18

Average kinetic energy of the particles

Question 19

Latent Heat

Answer 19

Heat energy used to overcome forces and change arrangement of particles into new state. This heat comes out when substance cools through change of state