14.Acid + Metal carbonate:? a. Salt + water + carbon dioxide
b. Salt + carbon dioxide
c. Salt + water + hydrogen
d. Salt + hydrogen

The answer is A.

Explanation:

When acid react with metal carbonate, it will form salt, water and carbon dioxide.

For example :

HCl + CaCO3 → CaCl + H2O + CO2

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.