Is the element krypton noxious?

I don't think so but it is in the noble gas section

No because it is a noble gas it would need to be put with an alkiline metal become even remotely toxic in any way. Because it krypton being in the noble gases it has only 1 electron and as you might know Alinline metals have 7 and every element wants to have 8. so by putting 7 and 1 together you get 8.

Answer two atoms of oxygen;