Question 29

All three statements about Earth's atmosphere and temperature are correct:

I. Without atmosphere, temperature would be well below freezing everywhere: Correct. Without the greenhouse effect of atmospheric gases, Earth's average temperature would be about -18°C (-0.4°F) instead of the current +15°C (+59°F), making the planet largely frozen.

II. Heat absorbed and trapped by atmosphere maintains planet's average temperature: Correct. The atmosphere acts as a thermal blanket, absorbing solar radiation and trapping outgoing longwave radiation, maintaining Earth's habitable temperature range through the greenhouse effect.

III. Atmospheric gases like CO₂ are particularly good at absorbing and trapping radiation: Correct. Greenhouse gases like carbon dioxide, methane, and water vapor effectively absorb infrared radiation emitted by Earth's surface and re-radiate it, creating the warming effect essential for life.