Graphite

Q.

Which of the following substances has free electrons to conduct electricity?

1. Diamond
2. Graphite
3. Wood
4. All the above

Q.

Graphite is a soft lubricant extremely which is difficult to melt. What is the reason for this anomalous behaviour?

1. It is a non-crystalline substance.

2. It has only single bonds between carbon atoms.

3. It has carbon atoms arranged in large plates of rings of strongly bound carbon atoms with weak interpolate bonds.

4. It is an allotropic form of carbon.

Q.

Name an allotrope of carbon which contains both single and double bonds between carbon atoms.

1. diamond

2. Graphite

3. Fullerene

4. No allotrope meets such a condition.

Q.

Graphite is a good conductor of electricity because it has

1. delocalised protons.
2. delocalised electrons.
3. no electrons.
4. localised electrons.

Q.

Number of free electron(s) in each carbon atom in graphite is/are:

1. 1
2. 3
3. 2
4. 4

Q. Which of the following statements are true regarding allotropes of carbon?

1. Graphite is extremely harder than diamond.
2. Graphite has higher electrical conductivity than diamond.
3. Graphite has higher thermal conductivity than diamond.
4. Graphite has lower density than diamond.

Q. Graphite has a _______ layered structure.

1. pentagonal
2. octagonal
3. triagonal
4. hexagonal

Q.

The pencil leads are made of mainly :
(a) lithium (b) charcoal (c) lead (d) graphite

Q. Name the element whose allotropic form is graphite.

Q. Name the black substance of pencil. Will the current flow through the electrical circuit when we use the sharpened ends of the pencil to complete the circuit ?