Question

Which is the odd one in oxygen, nitrogen, carbon dioxide, hydrogen peroxide

Answer 1

nitrogen because it can freeze a human

Answer 2

The answer should be carbon dioxide, because it is the only gas that is made up of two elements: carbon and oxygen.

All others, like oxygen, nitrogen and hydrogen peroxide have single bond.

Oxygen is only O, nitrogen is only N, and hydrogen peroxide is H2O2, which is made by combining two atoms of oxygen only.

So, carbon dioxide is the only element that has a combination of two different elements.