Answer;
Group 2
Explanation;
Strontium's highest occupied energy level is 5s2. It belongs to group 2.
Strontium belongs to group 2, alkaline earth metals.
It is a soft silver white yellowish metallic element that is highly reactive chemically.
Its electron configuration is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 5s2.