<span>Na2CO3 (aq) + CaCl2H4O2 (aq) = CaCO3 (s) + 2 NaCl (aq) + 2 H2O (l)</span>
Answer:
B I think I am pretty sure
The basic units for density is

and any get of units that has those units in the proper place can be considered a density unit. The ones that has those specifically are A, B, E and F
A. Combustion since it can’t be nuclear….?