Concept:At night, the ground becomes cold because it loses heat by radiating energy outward, and no sunlight is available to replace that heat.
Explanation:During the day, the ground absorbs energy from the sun and becomes warm.
At night, the sun does not shine on that part of the earth, so the ground receives no incoming solar energy.
The ground continues to emit infrared radiation, releasing its stored heat into the atmosphere.
This outward flow of heat causes the surface temperature to fall, making the ground cold.
Thus, the cooling of the ground at night is mainly due to the earth radiating heat to the atmosphere.
Answer:B. earth radiates heat to the atmosphere at night