UPSC Prelims 2012 Q14: Science & Technology – Materials & Engineering
Graphene is frequently in news recently. What is its importance?
1. It is a two - dimensional material and has good electrical conductivity.
2. It is one of the thinnest but strongest materials tested so far.
3. It is entirely made of silicon and has high optical transparency.
4. It can be used as conducting electrodes required for touch screens, LCDs and organic LEDs.
Which of the statements given above are correct?
- (a) 1 and 2 only
- (b) 3 and 4 only
- (c) 1, 2 and 4 only
- (d) 1, 2, 3 and 4
Answer: (c) 1, 2 and 4 only
Explanation
Graphene
Graphene is a single layer of carbon atoms arranged in a honeycomb pattern.
| Statement | Verdict | Fact |
|---|---|---|
| 1. It is a two-dimensional material and has good electrical conductivity | Correct | Only one atom thick; conducts better than copper |
| 2. It is one of the thinnest but strongest materials tested so far | Correct | About 200 times stronger than steel |
| 3. It is entirely made of silicon and has high optical transparency | Incorrect | It is made of carbon; it is indeed transparent |
| 4. It can be used as conducting electrodes for touch screens, LCDs and organic LEDs | Correct | Transparent and conducting, so ideal for screens |
Key facts:
| Feature | Detail |
|---|---|
| Isolated | 2004, at the University of Manchester |
| Nobel Prize | 2010, to Andre Geim and Konstantin Novoselov |
| Source | A single sheet of graphite |
| Relatives | Carbon nanotubes, fullerenes |
Answer: (c) 1, 2 and 4 only.
Why each option is right or wrong
- (a) Incorrect. Statement 4 is also true: it is used for touch-screen electrodes.
- (b) Incorrect. Statement 3 is false; graphene is carbon, not silicon.
- (c) CORRECT. Graphene is two-dimensional, strong, conducting and useful in displays.
- (d) Incorrect. Statement 3 is false.
Key point
Graphene: one-atom-thick sheet of carbon; strongest and thinnest known material; excellent conductor; transparent; Nobel 2010 (Geim and Novoselov).
Remember
Graphene = single layer of carbon.
Common mistakes
- Thinking graphene is made of silicon.
- Confusing graphene (one layer) with graphite (many layers).
- Forgetting the 2010 Nobel Prize.
Exam tip
Graph-ene comes from graph-ite, and graphite is carbon.
Sources
- Nobel Prize — The Nobel Prize in Physics 2010
- NCERT Class XI — Chemistry (The p-Block Elements: allotropes of carbon)