Q. Which of the following are allotropes of oxygen?

1. Dioxygen
2. Ozone
3. Tetraoxygen
4. Octaoxygen

Choose the correct answer using the codes given below:
Answer: 1, 2, 3 & 4
Notes: Dioxygen (O₂), ozone (O₃), tetraoxygen (O₄) and octaoxygen (O₈) are all allotropes of oxygen, differing in their molecular structures. Allotropy refers to the existence of an element in different forms in the same physical state. Hence, all the given forms are correct allotropes of oxygen.