2.1.1 Classification of an Element

Question 1

Label S, D, P and F block

Answer 1

Question 2

Reactions of Sodium with Water

Answer 2

2Na (s) + 2H2O (l) → 2NaOH (aq) + H2 (g)

• Na reacts vigorously with cold water
• Melts into ball moving across waters surface until it disappears
• H2 gas given off
• Strongly alkaline solution formed because of the NaOH formed

Question 3

Reactions of Mg with water

Answer 3

Mg (s) + 2H2O (l) → Mg(OH)2 (aq) + H2 (g)

Weakly alkaline solution, Mg(OH)2 only slightly soluble

when heated in steam, reacts vigorously to for MgO and H2