Question

1. which of the following elements is an alkaline earth metal? a) sodium c. oxygen b. helium d. calcium

Explanation:

Alkaline earth metals are in Group 2 of the periodic table. Sodium (Na) is in Group 1 (alkali metal). Helium (He) is a noble gas (Group 18). Oxygen (O) is a non - metal in Group 16. Calcium (Ca) is in Group 2.

Answer:

d. calcium