So to change the density, answers A and D

Hypothesis answer is B.

The Hypothesis is the first question you ask to solve a problem. ie “What is the effect adding an open flame to a puddle of gasoline”

When molecules are close together there is high density. When molecules are further appart there is less density. What can you do to decrease density? and what is the result of that process? If the molecules move further appart then what has happened?

Second, you begin with a hypothesis, it is a belief. then you run tests and analyze data and then come to a conclusion, then compare the conclusion with the hypothesis. Does it support the hypothesis, or contradict the hypothesis.

2- a hypothesis is just a guess or prediction, the answers aren’t worded very clear but I’d say (b)

Can’t guarantee that i’m right, but i hope it helps

question 2 it’s b.