Question

Which phrases describe air density? Check all that apply.

1. increases as altitude increases

2. equals mass divided by volume

3. pushes molecules in one direction

4. exerts more pressure as it increases

5. measures how tightly molecules are packed

Answer 1

The answers are 2, 4 and 5. On the contrary to choice 1, air density decreases with altitude. Some gases have denser than others meaning they have more mass per unit volume. Temperature and pressure also have an influence on air density.

Answer 2

Explanation:

Density is defined as the degree of compactness.

Also mathematically,       Density = $\frac{mass}{volume}$

That is density equals to mass per unit volume.

When we say air density has increased then it means the molecules of air has come more closer to each other. Also, increase in density will exert more pressure on the molecules.

Thus, we can conclude that phrases described by air density are as follows.

• equals mass divided by volume.

• exerts more pressure as it increases.

• measures how tightly molecules are packed.