Question

which group tends to form +1 ions?
Ca Ga
Li O
Cl S
Br As
Ba Sr
O S

Answer 1

Group 1 elements and certain Group 13 elements tend to form +1 ions.

Among the groups listed, **Li** (lithium) from the second option **(Li O)** is the only member that typically forms a +1 ion. Lithium is part of Group 1 (alkali metals), which typically form +1 cations.

So the group that tends to form +1 ions in your options is **Li** from the pair **(Li O)**.