2 answers:
I think it’s , the sum of all protons and neutrons in the atomic nucleus.
Apologize if it’s wrong .
The answer is B. Your welcome.
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Balanced equation:
Ca(OH)2+H2SO4=CaSO4+2 H20<span />
Answer:
That is a compound. If it was an element it would either just be Na or Cl.
1. 4NHCO3
2. 3CaCO3
3. 5NaC2H3O
4. 6NH3
5. 2CaCl2O2
ans ( a). NHCO3
