Question

Of these nonmetals, which one is likely to be the least reactive?

A. nitrogen (N)
B. phosphorous (P)
C. sulfur (S)
D. oxygen (O)

Answer 1

Reactivity increases upward and decreases leftward for these nonmetals. Thus oxygen would be the most reactive since it is the most rightward and upward.

Answer 2

Answer: Phosphorous

Step-by-step explanation: Nitrogen(N): 7:
`1s^22s^22p^3`

Phosphorus(P): 15:
`1s^22s^22p^63s^23p^3`

Oxygen(O): 8:
`1s^22s^22p^4`

Sulphur(S): 16:
`1s^22s^22p^63s^23p^4`

As nitrogen contains half filled configuration, it is stable and does not react. Phosphorous lies below nitrogen and reactivity decreases down a group for non metals as they tend to gain electrons as the valence shell move away from the nucleus.

Oxygen has 4 valence electrons, thus it need to gain two electrons to attain stable configuration. Thus is reactive.

Sulphur lies below oxygen and also need to gain two electrons. Reactivity decreases down a group for non metals as they tend to gain electrons as the valence shell move away from the nucleus.