Vocabulary
What is a noticeably different form or state of the same substance?
Phase
Solid
liquid to gas
evaporation
If you add energy into a substance, the molecules will _______.
Speed up or slow down
Speed up
Does energy transfer always result in a phase change?
Yes or No
No
The energy an object has because it is moving is called?
Kinetic energy
The molecules are close together but able to move around each other.
Liquids
solid to liquid
melting
If you transfer energy out of a substance, the molecules will _____.
Slow down
KE and molecular attraction
A pull between two molecules that is always the same for a substance
Molecular Attraction
Molecules fill the container and move apart.
Gas
liquid to solid
freezing
When you add energy into a substance, the molecules freedom of movement _______.
Increases or Decreases
Increases
If you transfer energy into two solid substances, which do you think would melt first?
a) a substance with a stronger attraction
b) a substance with a weaker attraction
a substance with a weaker attraction
The way molecules in a substance move around relative to each other.
Freedom of movement
What phase does the molecules take the shape of the container?
liquid
gas to liquid
condensation
When you remove energy for a substance, the molecules freedom of movement _______.
Speed up or Slow down
Slow down
If you transfer energy out of two substances in the gas phase, which do you think would condense first?
a) a substance with a stronger molecular attraction
b) a substance with a weaker molecular attraction
a substance with a stronger molecular attraction
The measure of how hot or cold something is
Temperature
What phase do the molecules stay at the bottom and are rigid?
Solid
Is burning considered a phase change?
Yes or No
NO
In what phase are the molecules KE the highest?
Solid, Liquid, or Gas
Gas
Earlier in the lesson, you observed isopropanol and water drops on a paper towel Even thought the same amount of energy was transferred into both substances from the air, the isopropanol evaporated while the water did not. Why did the isopropanol change phase, but the liquid did not?
The isopropanol had a weaker attraction than water. It required less energy transferred in to overcome the attraction.