Question

question 5.a
what would most likely happen to earths surface conditions if the planet had no atmosphere?
a. temperature changes would be mild and stable throughout the day and night and radiation levels remain the same.
b. temperatures would rise steadily until the surface became completely molten.
c. temperatures would vary drastically between day and night, and radiation levels would increase.
d. temperatures would decrease slightly, but most organisms could still survive.

Explanation:

The Earth's atmosphere plays a crucial role in regulating temperature (through processes like the greenhouse effect, heat retention, and insulation) and shielding from solar radiation (like UV and cosmic rays). Without an atmosphere:

• Option A: Incorrect. The atmosphere helps moderate temperature changes; without it, changes would be extreme, not mild. Radiation levels would also not remain the same (no shielding).
• Option B: Incorrect. While temperatures would be extreme, the surface wouldn't necessarily become completely molten. The Sun's energy and heat transfer processes don't support a steady rise to complete melting.
• Option C: Correct. During the day, without atmospheric insulation or reflection, heat from the Sun would heat the surface intensely. At night, without the atmosphere to retain heat, it would radiate away quickly, leading to drastic day - night temperature swings. Also, the atmosphere absorbs and scatters harmful radiation; without it, more radiation would reach the surface.
• Option D: Incorrect. Temperatures would vary drastically (not just decrease slightly), and most organisms would not survive due to extreme temperatures and high radiation.

Answer:

C. Temperatures would vary drastically between day and night, and radiation levels would increase.