What’s the answer to this

B and D as well

Explanation:

All the electronic configuration of the elements of B end on s sub shell.

S energy level sub shell can hold 2 electrons and since Be, Mg, Ca Sr end in s.

We can say, they have same valence electrons, i.e 2 electrons.

Explanation:

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.

the answer is c.the valence of the atoms combine .