Help please I have 10 min.

Iknow the answer is a but i don't know why

A50.0 ml sample of gas at 20.0 atm of pressure is compressed to 40.0 atm of pressure at constant temperature. what is the new volume? 0.0100 ml 0.325 ml 25.0 ml 100. ml

What happens to the glucose molecule during the process of cellular respiration? (5 points) select one: a. it gets broken down. b. it forms oxygen. c. it builds muscles. d. it uses up energy.