Question

why is mercury not the hottest planet when it is the one closest to the sun?? it has a large ozone layer it has no liquid water it has hardly any atmosphere to insulate it it has a very heavy atmosphere

Explanation:

The atmosphere plays a crucial role in heat - retention. Mercury has a very thin atmosphere, almost negligible. Without a substantial atmosphere to trap and retain the heat it receives from the Sun, the heat quickly escapes back into space. In contrast, Venus has a thick atmosphere with a strong greenhouse effect that makes it the hottest planet.

Answer:

it has hardly any atmosphere to insulate it