Qwesdfgudfdfdess de afefdfsfwrqdetgr
Answer:
C: 4
H: 1
Mg: 2
O : 6
Explanation:
You can quickly find out the number of valence electrons by looking at where the element is on the periodic table and referring to the table that is attached.
D will because water just turns from liquid to a gas by adding heat. That is a physical change. The other equations are chemical changes.