Graphene is frequently in news recently. What is its importance?<br/>1. It is a two-dimensional material and has good electrical conductivity.<br/>2. It is one of the thinnest but strongest materials tested so far.<br/>3. It is entirely made of silicon and has high optical transparency.<br/>4. It can be used as 'conducting electrodes' required for touch screens, LCDs and organic LEDs.<br/><br/>Which of the statements given above are correct?

1. Correct. Graphene is a two-dimensional sheet of carbon atoms arranged in a hexagonal lattice, and it has excellent electrical conductivity.

2. Correct. It is one-atom thick and is among the strongest materials tested, with very high tensile strength.

3. Incorrect. Graphene is made of carbon, not silicon; though it does have high optical transparency, the statement is wrong because of the material composition.

4. Correct. Due to its conductivity, flexibility and transparency, graphene can be used as conducting electrodes in touch screens, LCDs and organic LEDs.

Hence, statements 1, 2 and 4 only are correct.