What is the chemical formula for di-oxygen?

• A. O
• B. O2
• C. O3
• D. O4

Answer: (B)

The chemical formula for di-oxygen is represented as O2. This notation indicates that each molecule consists of two oxygen atoms bonded together. The prefix "di-" specifically denotes the presence of two atoms. In the context of molecular oxygen, O2 is essential for life as it is the form of oxygen that organisms, including humans, breathe to support cellular respiration.

Other options represent different forms of oxygen: O is a single oxygen atom, O3 refers to ozone, which consists of three oxygen atoms and has distinct properties and functions in the atmosphere, and O4 represents a hypothetical molecule that does not typically exist under standard conditions. Thus, O2 is the only correct representation for molecular di-oxygen.