Answer:
6 moles of oxygen, or 3O2.
Explanation:
I would build a proportion for this:

<span>a pure substance that can be separated into different elements by chemical means</span>
Well if the change is reversible then it is a physical change, but if not then it is a chemical change.
Answer:
heat and pressure
Explanation:
because it happens under heat and pressure.
Explanation:
the lone pairs will be negatively charged. these have a repulsion effect on other negatively charged electrons in the shells of atoms. picture a water molecule: the lone electron pair on the top of the oxygen will have a repulsion force on the 2 hydrogen atom's orbiting electrons to cause a bent molecular geometry.