Chapter 2

Question 1

Element

Answer 1

A substance that cannot be further divided into simpler substances by chemical methods; all atoms of an element have same proton number.

Question 2

Compound

Answer 2

A substance formed by the chemical combination of two or more elements in fixed proportions.

Question 3

Isotopes

Answer 3

Atoms of the same element wiht same proton number but different neutron number.

Question 4

Relative Atomic Mass

Answer 4

The average mass of naturally occuring atoms of an element on a scale C-12 has a mass of exactly 12 units.

Question 5

Ionic Bond

Answer 5

Strong electrostatic force of attraction between oppositely charged ions.

Question 6

Ionic Bond Properties

Answer 6

1. Good Conductors of heat and electricity.
2. High Melting and Boiling Points.
3. Exist as crystals in room temperature.
4. Soluble in water.

Question 7

Covalent Bond

Answer 7

The electrostatic force of attraction between nuclei of two atoms and the pair of electrons shared between them.

Question 8

Graphite

Answer 8

1.Each Carbon to three Carbon atoms.
2. Conducts Electricity
3. Layers cans lide over each other without breaking.
4. High Mp and Bp
5. Lubricant, Electrode, Pencil TIps

Question 9

Diamond

Answer 9

1. Each Carbon to 4 Carbon atoms.
2. Doesn’t Conduct Electricty
3. Hard
4. High Mp and Bp
5. Cutting Tools and Jewellery.

Question 10

Silica

Answer 10

1.Each Silicon to Four Oxygen to 2 Silicon.
2.Hard
3. High Mp and Bp
4. Doesn’t conduct electricity
5. Sandpaper, Furnace Lining