Question

if mercury is closer to the sun, why is the nighttime average temperature lower than that of earth?
the atmosphere on earth is thicker than the atmosphere on mercury
the atmosphere on earth is thinner than the atmosphere on mercury
the length of time it takes mercury to revolve around the sun is longer than earths
the length of time it takes mercury to revolve around the sun is shorter than earths

Explanation:

The atmosphere on Earth is thicker than that on Mercury. A thicker atmosphere helps to trap heat (like a greenhouse effect). Mercury has a very thin (almost non - existent) atmosphere, so it can't retain heat well at night. The length of time to revolve around the Sun (orbital period) is not directly related to nighttime temperature in this context.

Answer:

The atmosphere on Earth is thicker than the atmosphere on Mercury.