Question 1 (2 points) What state of matter is achieved if a large amount of energy is added to a gas? (2 points)

a
Vapor

b
Liquid

c
Plasma

d
Solid

Question 2 (2 points)
What happens to a gas when its temperature decreases? (2 points)

a
The gas becomes a plasma.

b
The molecules move more slowly.

c
The energy of the particles increases.

d
The atoms in the gas are destroyed.

Question 3 (2 points)
Mary and Ron are discussing what happens to the kinetic energy of molecules in a liquid as the liquid cools. Mary says it decreases. Ron says it stays the same. Who is correct and why? (2 points)

a
Mary is correct, because molecules are constantly losing kinetic energy no matter what state they are in.

b
Mary is correct, because as the liquid cools, the molecules slow down as they lose kinetic energy.

c
Ron is correct, because kinetic energy is a fixed characteristic of molecules and does not change.

d
Ron is correct, because kinetic energy can only increase, not decrease.

Question 4 (2 points)
Which quantity is directly related to the temperature of a substance? (2 points)

a
Average kinetic energy of the particles in the substance

b
Average size of the particles in the substance

c
Composition of the substance

d
pH of the substance

Question 5 (2 points)
As heat is added to a tube of gas, which is the most likely phase transition to occur in the tube? (2 points)

a
Gas to plasma

b
Gas to liquid

c
Gas to solid

d
Gas to element

Question 6 (2 points)
How do elements change as you move down a column in the periodic table? (2 points)

a
The atomic radius decreases.

b
The number of protons decreases.

c
The atomic mass decreases.

d
The electronegativity decreases.

Question 7 (2 points)
How are chemical and physical changes different on a molecular level? (2 points)

a
Chemical changes involve the breaking of bonds in molecules.

b
Chemical changes do not affect bonding between atoms.

c
Physical changes do not involve molecules.

d
Physical changes cause new molecules to form.

Question 8 (2 points)
How does the currently accepted model of the nucleus provide evidence of the existence of the strong nuclear force? (2 points)

a
The protons have like charges and should repel, so to stay near each other in the nucleus, there is a strong force holding them together.

b
The electrons have like charges and should repel each other, which is why they are scattered in the electron cloud.

c
The protons and neutrons have opposite charges and should attract each other, so to keep them apart, there must be a strong force in the nucleus.

d
The particles in the nucleus are separated by type, showing the existence of a strong force that keeps them apart.

Question 9 (2 points)
How do scientific models become stronger over time? (2 points)

a
New experiments verify or refine previous models.

b
As more people believe the model, it is stronger.

c
Older theories are always thought to be stronger than new theories.

d
Personal beliefs become more important to scientists over time.

Question 10 (2 points)
When scientists publish experimental results, their results are often criticized by other scientists. How is this process a source of strength of science? (2 points)

a
It encourages scientists to give convincing evidence for their results.

b
It allows scientists to keep their data secret.

c
A scientific model is not useful unless everyone thinks it is true.

d
It forces scientists to publish results that are in line with current theories.