An atom has atomic number 20, in which group and in what period is this atom located?

Element: Calcium

Group: 2A/IIA(alkaline earth metals)

Period: 4

if the concentration of products is decreased, the equilibrium will shift toward the products). add an inert gas (one that is not involved in the reaction) to the constant-volume reaction mixture: this will increase the total pressure of the system, but will have no effect on the equilibrium condition.

explanation:

wher is the rest of the question