CP12-Particle Model

Question 1

Particles and Density

Answer 1

Kinetic Theory- Everything is made of tiny particles
-When a substance undergoes a change of state the particles end up in a different arrangement. This is a physical change
Density- The mass of a certain volume of the substance
Arrangement of particles can explain the differences in density between different states of matter
Density Formula:
Density = Mass/Volume

Question 2

Energy and changes of state

Answer 2

Temperature- Measure of the movement of particles
The amount of thermal energy stored in something depends on- Its temperature, Mass, Material
Specific Heat Capacity- The amount of energy it takes to increase the temperature of 1 kilogram of the substance by 1 degree.
When enough energy is transferred to a solid it reaches its melting point.
Specific Latent Heat- The amount of energy it takes to make 1kg of a substance change state is called the specific latent heat.

Question 3

Energy Calculations

Answer 3

Change in thermal energy= Mass X Specific Heat Capacity X Change in temperature
Energy is needed to make a substance melt or evaporate. The amount of energy depends on the mass of the substance and on its specific latent heat
Thermal Energy needed to change state= Mass X Specific Latent Heat

Question 4

Gas, Temperature and Pressure

Answer 4

Temperature of a gas is a measure of the average kinetic energy of the particles in it
The faster the average speed of the particles, the higher the temperature. Heating a gas increases energy, so they speed up.
The pressure of a gas is due to forces on the walls of a container caused by moving the particles hitting the walls. Faster the particles are moving, the higher the amount of collisions and higher the pressure. Pressure is measured in pascals.
Absolute Zero- -273 Degrees C