Arrange the following substances in chronological order of their first synthesis in lab:
1. Black gold 2. Fullerene 3. Graphene 4. Kevlar
Select correct answer from the codes given below:
- A1 2 3 4
- B4 2 3 1
- C2 4 3 1
- D4 1 2 3
Show answer and explanation
Correct answer: (b) 4 2 3 1
Explanation
Kevlar (1965) came first, made by condensation of an amine and acid chloride into rigid aramid sheets.
Fullerene (1985) followed, a closed cage allotrope of carbon, then Graphene (2004), a single hexagonal sheet of sp² carbon.
Black gold here is not petroleum but a gold nanomaterial that absorbs almost all visible light, made after graphene (scientists at TIFR, Mumbai, reported one in 2019), so the order is 4–2–3–1.