Of these nonmetals, which one is likely to be the least reactive?
a. nitrogen (n)
b. phosphorous (p)
c. sulfur (s)
d. oxygen (o)

Phosphorous

Explanation: Nitrogen(N): 7:

Phosphorus(P): 15:

Oxygen(O): 8:

Sulphur(S): 16:

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.

fire could start, buildings collapsing, and ash falling from the sky.

explanation:

this is because the buildings or plants could catch on fire and the buildings would most likely collapse. lastly ash would fall because all the burning would cause ash to fall from the sky.

hope this .