A sample of oxygen contains  ${\mathrm{O}}^{16}$ and ${\mathrm{O}}^{18}$ isotopes only with percentage abundance  respectively as $90\%$ and $10\%$. Identify the correct option(s):

 

Average number of protons per atom is 8 

Average atomic mass of sample is 16.2.

Molecular mass of oxygen gas which can be formed from the sample can vary from $32$ to $36$

Average number of neutrons per atom is $8.2$