Particle model GapFill

The particle model of matter describes the different states of matter in terms of the particles that make them up. The least dense state of matter is  energyfiregassolid, which has particles spread far apart with no bonds between particles. The next least dense state of matter is  oilliquidgaswater, which has weak bonds between its particles, but these particles can still move past each other. The most dense state of matter is  liquidsoliddiamondmetal, which has particles very close together with strong bonds between these particles.
Substances can change from one state of matter to another; for example:

• Melting is the state transition from  solid to liquidsolid to gasliquid to solidgas to solid.
• Sublimation is the state transition from  gas to plasmasolid to liquidliquid to gassolid to gas.
• Evaporation is the state transition from  solid to gasgas to solidgas to liquidliquid to gas.

These state changes are  chemical changesatomic changesphysical changesmolecular changes, and they are reversible.

Density (ρ) is calculated by using the equation  ρ = mVρ = m ÷ Vρ = m × depth in the waterρ = fV. The volume of an irregular solid can be determined using a Eureka can and is equivalent to  the displacementthe amount of fluid displacedthe volume of fluid displacedwhat remains in the can.

The internal energy of a system is the total  thermalkinetickinetic and potentialpotential energy in the system, which can be increased by heating. This either increases the temperature of the system (which depends on the  densityspecific latent heatthermal conductivityspecific heat capacity and mass of the objects in the system) or changes the state of the system (how much of the system changes state depends on the  specific latent heatdensityspecific heat capacitythermal conductivity of the materials in the system). While an object changes state,  its temperature and internal energy stay the sameits temperature decreases and its internal energy decreasesits internal energy stays the same and its temperature increasesits temperature stays the same and its internal energy increases.

Particles in a gas are in constant random motion. The temperature of a gas is related to  the average kinetic energythe chargethe sizethe mass of the particles in the gas. When the temperature of a gas in a fixed container increases, the pressure of the gas increases because  the particles begin to rotatethe particles try to get away from each otherthere are more particlesthe particles hit the sides of the container at higher speeds. When the pressure of a gas is increased, the temperature of the gas increases because  the particles stop movingthe particles do work on each otherthere are more particleswork done on the gas increases its internal energy.