Matter: Changes of States
What is necessary to change one state of matter into another?
The answer is ENERGY
STATES OF MATTER BY INCREASING ENERGY
The following is a graph that shows the states of matter by increasing amount of energy from bottom to top.
Changes, one by one
FREEZING or SOLIDIFICATION:
Liquid to Solid.
FREEZING POINT:
The temperature in which a Liquid changes to solid. Example: Water freezes at 0⁰C.
Hint: Compare this with the melting poing!
MELTING:
Solid to liquid.
MELTING POINT:
The temperature in which a Solid changes to Liquid. Example: Ice melts at 0⁰C
Deposition:
Gas to Solid.
SUBLIMATION:
Solid to Gas.
Some substances do not melt but they pass from solid to gas directly. this process is called Sublimation
CONDENSATION:
Gas to Liquid.
CONDENSATION POINT:
The temperature in which a Gas changes to liquid. Example: Water condenses at 100⁰C.
VAPORIZATION:
Liquid to Gas.
EVAPORATION OR BOILING?
BOILING:
Liquid to Gas.
Boiling occurs through out all the liquid and only when the liquid reaches the boiling temperature.
BOILING POINT:
The temperature in which a liquid turns into a gas. Example: pure water vapor boils at 100⁰C.
EVAPORATION:
Liquid to Gas.
Evaporation occurs:
- AT ANY TEMPERATURE
- ONLY ON THE SURFACE
- THE HIGHER THE TEMPERATURE, THE FASTER EVAPORATION.
All changes in one graph
Heating Curves
- A heating curve represents the change in temperature and phase transitions that a substance undergoes as heat is added to it. like in the graph below:
- The plateaus on the curve mark the phase changes (changes in state of matter). The temperature remains constant during these phase transitions.
- The first change of phase is melting, during which the temperature stays the same while water melts.
- The second change of phase is boiling, as the temperature stays the same during the transition to gas.
Cooling Curves
- A cooling curve represents the change in temperature and phase transitions that a substance undergoes as heat is taking out from it. like in the graph below:
- The plateaus on the curve mark the phase changes (changes in state of matter). The temperature remains constant during these phase transitions.
- The first change of phase is condensation, during which the temperature stays the same while water condenses from gas to liquid.
- The second change of phase is freezing, as the temperature stays the same during the transition to solid.
Heating Curve of water
