CBSE Class 7 Science The Language of Chemistry Assignment

Q.1 Write the symbols of the following elements

1) Zinc 6) Phosphorus

2) Manganese 7) Nickel

3) Potassium 8) Calcium

4) Calcium 9) Lead

5) Gold 10) Neon

Q.2 Find the valencies of the underlined element

1) BaCl₂

2) FeO

3) Fe₂O₃

4) CaCO₃

5) Na₂O

6) Al(OH)₃

7) SO₂

8) NH₃

Q.3 Define.

1) Valency 4) Molecule

2) Formula 5) Compound radical

3) Symbol 6) Balanced chemical equation

Q.4 Write the formula of the following compounds

1) Nitric acid 5) Potassium carbonate

2) Ammonia 6) Calcium dioxide

3) Sodium hydroxide 7) Carbon monoxide

4) Hydrogen chloride 8) Sulphuric acid

Q.5 Give examples each of the following.

1) Binary compound 5) Trivalent

2) Monovalent 6) Triatomic gas

3) Divalent 7) Noble gas

4) Diatomic gas

Q.6 Write the valency/valencies of the following

1) Hydrogen 5) Iron

2) Carbon 6) Copper

3) Nitrogen 7) Sulphur

4) Phosphorus 8) Lead

Q.7 Balance the chemical equation

1) Mg + O₂ → MgO

2) N₂ + O₂ → NO

3) CH₄ + O₂→ CO₂ + H₂O

4) NO₂ + H₂O → NO + HNO₃

Q.8 Match the following.

          A                   B

1) Potassium    a) Aurum

2) Iron              b) Stannum

3) Silver           c) Ferrum

4) Gold            d) Argentum

5) Tin               e) Kalium