physics topic three Flashcards
what is density
Density is a measure of how close particles are in
a substance
describe Measuring density REQUIRED PRACTICAL
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
give features of solids
- 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
give features of liquids
- particles close together
- no room for particles to move closer – can’t be compress
- particles free to move around – no fixed shape
give features of gases
- particles far apart
- space between particles so easy to compress
- move randomly at a range of speeds
- spread out in all directions
what is temperature
Temperature is the average kinetic energy of a substance
what happens when you increase the temperature of something
you increase its kinetic energy store
what is specific latent heat of fusion
Amount of energy required to change 1Kg of a solid to a liquid OR a liquid to a solid
what is specific latent heat of vaporisation
Amount of energy required to change 1Kg of a liquid to a gas OR a gas to a liquid
talk about changes of state on an inter molecular scale
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
when does pressure occur
Pressure occurs when particles collide with each
other and the walls of the container
what factors effect pressure in gas
- ↑ Temperature = ↑ Pressure
- ↓ Volume = ↑ Pressure (if number of particles
are kept the same) - ↑ particles = ↑ pressure.
