Allotropy

Q. Why are the various allotropes of carbon have different chemical and physical properties?

1. Different structure of carbon atoms

2. Different bonding pattern among carbon atoms

3. Different temperature gradient across carbon atoms

4. Different number of valence electrons in the carbon atoms.

Q. Carbon forms innumerable compounds because-

1. It has electrons in its outermost shell
2. It behaves both as a metal and nonmetal
3. It combines with other elements to form covalent bonds
4. It is stable

Q.

What are allotropes? Name any two allotropic forms of carbon. Give one use of it.

Q.

Identify the substance in which carbon exists in the free state.

1. Cellulose

2. Graphite

3. Carbon dioxide

4. Petroleum

Q. The phenomenon by which an element exists in two or more different crystalline or amorphous forms is called allotropy.

1. True

2. False

Q. The atomic number of carbon is ______.

1. six
2. four
3. eight
4. twelve

Q. Choose the properties exhibited by an element carbon.

1. Mass number = 6
2. Tetravalency
3. Covalency
4. Catenation
5. Small size
6. Allotropy
7. Inert gas
8. Ionic bond

Q. In a $H_2$ molecule, one pair of electrons is shared between the two hydrogen atoms.

1. False
2. True

Q. Which is not a noble metal?

1. Gold
2. Osmium
3. Iridium
4. Iron

Q. Autoignition temperature is the highest temperature at which a substance can burn.

1. True
2. False

Q. In the periodic table, carbon belongs to the category of _________.

1. metals
2. metalloids
3. nonmetals
4. noble gases

Q. , the self linking property along with , helps carbon atoms to make large number of chains and rings.

1. Catenation
2. tetravalency
3. Allotropy
4. nuclear charge

Q.

Explain about catenation and tetra valency of the carbon?

Q. Silicon is also tetravalent. But why can’t it form long chain compounds like carbon?

1. Silicon does not form polymers because of its semiconductor nature.
2. Carbon is small in size, so holds the shared electron pair strongly.
3. Silicon compounds are highly reactive
4. Carbon compounds are unreactive.

Q. Carbon is found in its native state in all the given compounds except .

1. coal
2. diamond
3. carbon dioxide

Q. Which amongst the following molecules consist of a triple bond?

1. Hydrogen
2. Fluorine
3. Nitrogen
4. Oxygen

Q.

Apart from Carbon, which other elements commonly form allotropes?

1. Sulphur and Boron.

2. Oxygen and Phosphorus

3. Oxygen, Phosphorus and Barium

4. Oxygen, Phosphorus and Sulphur