Question

which element is classified as an alkali metal?
rb
sr
zr
cl

Explanation:

Alkali metals are in Group 1 of the periodic table. Rb (rubidium) is in Group 1. Sr (strontium) is in Group 2 (alkaline - earth metals), Zr (zirconium) is a transition metal, and Cl (chlorine) is a halogen.

Answer:

A. Rb