Which oxidation state is typical for Group 2 elements in compounds?

Which oxidation state is typical for Group 2 elements in compounds?

• A. 0
• B. +2
• C. -2
• D. +1

Answer: (B)

Group 2 elements have two valence electrons and tend to lose both to reach a stable, noble-gas electron configuration. In compounds they therefore form M2+ ions, which is balanced by two negative charges from the surrounding anions. That’s why salts like MgCl2 and CaCO3 exist with the metal in the +2 oxidation state. Seeing the elemental state (oxidation state 0) isn’t typical for a metal in a compound, and -2 would be anions like oxide or sulfide rather than a metal’s oxidation state. A +1 state would imply losing only one electron, which isn’t the common behavior for these metals. Higher oxidation states are not typical for Group 2 in ordinary chemistry, making +2 the standard choice.

Group 2 elements have two valence electrons and tend to lose both to reach a stable, noble-gas electron configuration. In compounds they therefore form M2+ ions, which is balanced by two negative charges from the surrounding anions. That’s why salts like MgCl2 and CaCO3 exist with the metal in the +2 oxidation state.

Seeing the elemental state (oxidation state 0) isn’t typical for a metal in a compound, and -2 would be anions like oxide or sulfide rather than a metal’s oxidation state. A +1 state would imply losing only one electron, which isn’t the common behavior for these metals. Higher oxidation states are not typical for Group 2 in ordinary chemistry, making +2 the standard choice.