Decide which element probably formed a compound with hydrogen that has a chemical formula most and least similar to the chemical formula of the compound formed by hydrogen and nitrogen

Most similar to nitrogen: Phosphorus

Least similar to nitrogen: Strontium

Explanation:

The options are missing but I looked on the web and I think these are:

Most similar to nitrogen

N and H form the compound NH₃. P is a nonmetal in the same group as N in the Periodic Table (Group 15) so it has similar chemical properties. In fact, P and H form the compound PH₃, a non-metallic hydride as NH₃.

Least similar to nitrogen

Sr is a metal, which is in the Group 2 in the Periodic Table (alkaline earth metal), so it is very different from N, and it forms a metallic hydride SrH₂.