SSTATES OF MATTER AND PHASE CHANGE PROCESSES
Differentiate between the three states of matter
|Have fixed volume
and fixed shape
|Have fixed volume
But have variable shape
And variable shape
What are the various types of phase changes?
Five types of phase changes
|Name of Process
|Solid to liquid
|Melting of ice, Gold, Silver and Cast Iron
|Liquid to solid
|Freezing of water into ice, milk into milk powder
|Liquid to gas
|Water into steam, liquid refrigerant into vapor refrigerant in a fridge/air conditioner/water cooler
|Gas to liquid
|Steam into water in the steam condenser, Vapor refrigerant to liquid refrigerant in the condenser of a fridge/air conditioner/water cooler
|Solid to gas
|Dry ice changes directly to carbon dioxide gas
|Gas to a solid
|When carbon dioxide gas changes into dry ice
|When a gas changes into a plasma
|Neon lights created by an electric current
|When plasma changes into a gas
|Turn off the power to a neon light, the ionized particles will return to the gas phase.
Phase Change Process
Matter is anything that has mass and occupies space. Matter exists as solids, liquids, gases, and plasma states. A solid is any matter which has a definite shape and volume. A liquid is any matter which has a definite volume but no definite shape. A gas is any matter which does not have a fixed shape or volume. Plasma is matter which exists in the form of high energy charged particles.
A phase change process of change of matter from one state to another state. Phase changes occur regularly in nature and can also be achieved otherwise. The change of phase depends on the pressure and temperature of the matter and its surroundings. Therefore, by controlling the pressure and temperatures, phase change can be make to take place.
Different types of phase changes
Phase change temperature depends on pressure. These increase with the increase of pressure and decrease with the decrease of pressure. For example, boiling point of water is 1000C at 1 atmospheric pressure. It becomes 120 and 1350C at 2 and 3 atmospheric pressures respectively. There are in all eight phase changes that can occur. These are the followings:
- Freezing: When a liquid changes into a solid at its freezing temperature.
- Melting : when a solid changes directly into a liquid at its melting temperature.
- Condensation: When a gas changes directly into a liquid at its condensation temperature.
- Vaporization: When a liquid changes directly into a gas at its vaporization temperature.
- Sublimation: When a solid changes directly into a gas.
- Deposition: When a gas changes directly into a solid.
- Ionization: When a gas changes to plasma.
- Recombination: When plasma changes to gas.