Question

Explain the gradation in properties (valency, metallic and non metallic character) of elements in the modern periodic table. [3 MARKS]

Answer 1

Each point: 1 Mark

1. Valency: Valency of elements remains the same while going down a group. When we move across a period, the valency of elements increases up to group 14, then decreases up to group 18.
2. Metallic properties: Moving down a group of metals, metallic nature increases due to increasing size. Going across a period, the metallic character decreases.
3. Non-metallic properties: In a group of non-metals, the non-metallic character decreases on going down. Going across a period, the non-metallic character increases.