Question

Which of the following is an element?
I) Oxygen gas
ii) Carbon dioxide gas
III) sulphur dioxide gas
iv) Nitrogen dioxide gas​

Answer 1

Answer:

All if these are elements

Answer 2

Answer:

i) oxygen gas

Explanation:

Since oxygen gas contains only oxygen atom, hence it is an element. Other options are compounds, as they comprise of two or more than two types of elements. Nitrogen dioxide gas contains nitrogen and oxygen.