Physical and Chemical Properties
What is a physical property?
A property that can be studies without changing what kind of matter is being studied
Example: Color, mass, density, buoyancy
Are solids easily compressed?
No! The molecules in a solid are already closely packed together, so they are difficult to compress
What is the measure of how strongly the molecules of a liquid are attracted to each other?
Which state of matter has the highest kinetic energy?
Gas - the molecules are not attracted to each other, and they move around a LOT
What is Boyle's Law?
As pressure on a gas increases, the volume of the gas decreases
This is an inverse relationship between gas pressure and volume
What is a chemical property?
A property that describes how a substance reacts in the presence of other substances to form new substances.
Example: When you put vinegar and baking soda together, they react to form gas bubbles
True or False:
Solids have a defined shape and volume
True!
Do liquids have low, moderate, or high kinetic energy?
Moderate Kinetic Energy
Do liquids have to boil in order to evaporate and become gases? Why or why not?
No - evaporation is possible at room temperature because higher energy liquid molecules can escape through the surface
What is Charles's Law?
When temperature increases, the volume of gas also increases.
Greater temperature = more kinetic energy, so the molecules move faster and spread out further
This is a direct relationship
Physical Change or Chemical Change:
Photosynthesis
Chemical!
Carbon dioxide and water molecules form sugar and oxygen molecules
What is the name for the phase change of a solid to a liquid?
Whatever the shape of the container it is put in
What causes gas pressure?
Gas molecules bounce off of each other and want to diffuse outward, so they create gas pressure when you put a lot of air inside something like a balloon or ball.
Would a soccer ball feel fuller on a hot day, or a cold day?
A hot day - Charles's Law says the volume of the gas will increase with higher temperatures
Physical or Chemical Change:
Salt dissolving into water
Physical! The salt can be recovered, this change is reversible
How are solids formed?
When a liquid is cooled down enough, it becomes a solid - freezing
True or False:
Liquids have no defined volume
False
Does gas have a defined volume?
What is an example of a chemical change other than photosynthesis?
Baking soda and vinegar, elephant toothpaste
a. They have high kinetic energy, and molecules that are not attracted to each other
b. They have moderate kinetic energy
c. They have low kinetic energy, and molecules that are strongly attracted to each other
c. They have low kinetic energy, and molecules that are strongly attracted to each other
When a liquid is boiled, what state of matter would it turn to?
Gas - evaporation
What is atmospheric pressure?
The pressure that is applied by the gas in the air around us
If I wanted to increase the volume of a gas, what are two ways for me to do that?
Decrease pressure, increase temperature