P3: Particle Model

• The state of matter which is most dense, is a solid
• A liquid has particles that are close together but can move around freely.
• In a gas the particles have lots of space between them so they move very quickly and randomly.
• The state of matter which is least dense, is a gas
• Internal Energy = Kinetic energy + Potential Energy
• Specific Heat Capacity is the amount of energy needed to raise the temperature of 1kg of a substance by 1 degree
• The change of state is shown as a flat point on a temp vs time graph, when heating a substance
• Particles in gases and liquids move randomly
• The greater the temperature, the more kinetic energy is carried by the particles
• You can measure the volume of an irregular object by using a eureka can. The euraka can be filled with water and the amount of water that spills out of the can, when an object is placed inside, is the volume.
• You can measure the volume of a regular object by using a ruler
• All matter contains particles
• In a solid, particles are tightly packed, in a regular structure.
• In a liquid, particles are tightly packed, but are free to move around
• In a gas, particles are spread out and move randomly
• Density describes how closely packed the particles are in a substance.
• Density = Mass / Volume
• Density can be measured in g/cm3 or kg/dm3
• Adding (heating) or removing (cooling) energy from a material can change its state.
• Changes in state are called physical changes because the process can be reversed
• The energy required for a particular change in state is given by the Specific Latent Heat (SLH)
• Latent heat of fusion = the amount of energy needed to freeze or melt a substance, at its melting point
• Latent heat if vaporisation = the amount of energy needed to boil or condense a substance, at its boiling point.
• SHC = heat energy / (mass x change in temp)
• Specific Heat Capacity is measured in J/KgC
• SLH = energy / mass
• Specific Latent Heat is measured in J/kg