Answer:

Explanation:
This reaction type is a single replacement. The format of a single replacement is:

A= Al
B= Ni
C= SO
The coefficient 3 for Ni would become a subscript for AC. After you plug those into the reaction you need to count how many of each are on the left side and try to get the same number on the right side. Both sides must be equal to have a balanced equation.
Answer: A. Is decomposition
B. Is synthesis where Na combines with Cl to form NaCl
C. Is single displacement or replacement. Mg displaces Cu.
Explanation:
Cu+ p=29 e=28 n=34
S2- p=16 e=18 n=16
Pb4+ p=82 e=78 p=125
I hope i did it right :))
The various atomic masses of the same element are called<u> isotopes</u>. They have the same number of protons but different number of neutrons.