Answer:
B. chemical processes
Step-by-step explanation:
The conversion of CO2 into carbonates is a type of chemical process.
A carbonate is a polyatomic ion with a chemical formula CO3^2- . From atmosphere CO2 can be easily converted into carbonates. Dissolution of carbon dioxide (CO2) into water (H2O) leads to the conversion of CO2 into carbonic acid (H2CO3) which comprises a carbonate ion. This carbonate ion then further reacts with either magnesium or calcium ion to produce calcium carbonate or magnesium carbonate which are carbonic salts of these metals.
The reactions are shown as under :
H2O + CO2 <=> H2CO3 (carbonic acid)
H2CO3 <=> H+ + HCO3^- (bicarbonate ion) <=> 2H+ + CO3^2- (carbonate ion)
Ca2+ + CO3^2- <=> CaCO3 (Calcium carbonate).
Similarly, magnesium can also react with carbonate ion.
Since each species is reacting chemically, these are regarded as a chemical process (chemical reactions).