Question

select all that apply select the statements below that correctly predict changes in air density. assume only the mentioned factors will change. if an air mass gains water vapor, its density will increase. if an air mass gains in altitude, its density will decrease. if the temperature of an air mass increases, its density will increase. if an air mass warms and gains in altitude, its density will decrease.

Explanation:

• Water vapor is lighter than dry - air. So, when an air mass gains water vapor, its density decreases, not increases.
• As altitude increases, air pressure decreases and air molecules spread out, causing density to decrease.
• When temperature increases, air expands and its density decreases according to the ideal - gas law.
• Warming an air mass causes it to expand (lower density), and increasing altitude also causes density to decrease. So, when an air mass warms and gains in altitude, its density will decrease.

Answer:

• If an air mass gains in altitude, its density will decrease.
• If an air mass warms and gains in altitude, its density will decrease.