physics topic three

Question 1

what is density

Answer 1

Density is a measure of how close particles are in
a substance

Question 2

describe Measuring density REQUIRED PRACTICAL

Answer 2

1) Measure mass using a balance
2) Measure volume of regular objects with a ruler (length x width x height)
3) Measure volume of irregular objects using either:
- measuring cylinder part filled with water, put object inside, final volume - initial volume
- fill eureka can with water, put object inside, volume of water displaced = volume of object
4) Calculate density using ρ = m / V

Question 3

give features of solids

Answer 3

• particles close together
• no room for particles to move closer – cant be compressed
• vibrate about fixed point
• strong forces of attraction
• particles not free to move around – fixed shape

Question 4

give features of liquids

Answer 4

• particles close together
• no room for particles to move closer – can’t be compress
• particles free to move around – no fixed shape

Question 5

give features of gases

Answer 5

• particles far apart
• space between particles so easy to compress
• move randomly at a range of speeds
• spread out in all directions

Question 6

what is temperature

Answer 6

Temperature is the average kinetic energy of a substance

Question 7

what happens when you increase the temperature of something

Answer 7

you increase its kinetic energy store

Question 8

what is specific latent heat of fusion

Answer 8

Amount of energy required to change 1Kg of a solid to a liquid OR a liquid to a solid

Question 9

what is specific latent heat of vaporisation

Answer 9

Amount of energy required to change 1Kg of a liquid to a gas OR a gas to a liquid

Question 10

talk about changes of state on an inter molecular scale

Answer 10

When a substance is heated
Its temperature increases

Until it reaches the melting or boiling point

At this point, heat energy goes to BREAK the bonds

Question 11

when does pressure occur

Answer 11

Pressure occurs when particles collide with each
other and the walls of the container

Question 12

what factors effect pressure in gas

Answer 12

• ↑ Temperature = ↑ Pressure
• ↓ Volume = ↑ Pressure (if number of particles
  are kept the same)
• ↑ particles = ↑ pressure.