The presence of an enzyme within a chemical system

decreases  activation energy.

Explanation:

This is the only answer I can find!

on the planet jupiter, the acceleration due to gravity is approximately 26 m s2 , roughly 2.7 times the acceleration due

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds