Exercise 1

CHAPTER 4

Exercise 11. (a) (i) group (ii) period (iii) proton number

(b) Increasing proton number.

(c) Same chemical properties.

(d) (i) Group 1 (ii) Group 17 (iii) Group 18

2. (a) False (b) True (c) True (d) True (e) False (f) True

Exercise 21. (a) Atomic substance (b) Molecular substance (c) Ionic substance

2.

Substances made of atomsSubstances made of moleculesSubstances made of ions

Gold

Potassium

LeadSulphur

Naphtalene

Carbon dioxideSodium chloride

Copper sulphate

Zinc bromide

3. (a) (i) Y

(ii) Cannot conduct electricity in solid state but can conduct electricity in liquid/ molten

state.

(b) (i) X

(ii) Cannot conduct electricity in solid state and liquid state.

4.

Physical propertiesSilverIodineSodium chloride

Physical state at room conditionSolidSolidSolid

Melting/boiling pointHighLow High

Electrical conductivityYesNoCan conduct electricity in molten form.