It's the balance of chemical equation.
Answer:
H+ + Cl- + OH- + Ca2+ -> Na+ + Cl- + H2O
Explanation:
Answer:
The coloring and possibly testing it
C) Weathering can be chemical or physical; deposition
is only chemical
Answer:
228
Explanation:
alpha decay is removing alpha particle 
2 number of protons, 4 mass number = 2 protons + 2 neutrons
We have
90 protons and 142 neutrons
<u> - 2 protons - 2 neutrons</u>
88 protons 140 neutrons
Mass number of new (daughter) atom = 88 +140 = 228