ANSWER FAST PLEASE Which are conserved during a chemical reaction?
A. molecules and volume
B. mass and atoms
C. volume and mass
D. atoms and molecules

Your Answer is A

Explanation:

the atomic mass is the bottom number on the element.

-steel jelly

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.