Which of the following is NOT an allotrope of carbon?
Answer & explanation
Correct answer: option 2
The correct answer is option 2. Methane.
Among the options provided, methane (option 2) is not an allotrope of carbon. Methane is a compound composed of one carbon atom and four hydrogen atoms \((CH_4)\), whereas graphite, diamond, and C-60 Buckminster fullerene are all allotropes of carbon.
So, the correct answer is 2. Methane.