A gas is at 9°C. To what temperature must it be heated to double the rise speed of its molecule!

Answer in units of C.

The answer is water molecules are split.cellular respiration and photosynthesis are complement  reactions to each other. these are reverse reactions. in cellular respiration glucose and oxygen yield water and carbon dioxide. so, when respiration begins,  glucose molecules are split. in the opposite reaction - in photosynthesis, carbon dioxide and water yield glucose and oxygen. thus,  when respiration begins, water molecules are split.

Answerconvection

The planets go around the sun..

Ican’t exactly answer this, but i can try to give a bit more info here.
astronomers are able to calculate a star’s life expectancy depending on its mass. (a larger star burns more gas, therefore having a shorter life span).
so astronomers can definitely predict the death of stars and the times they will die.
i hope this was in some way : )