Question 19 - Past Year - 3 Mark Questions - Chapter 5 Class 10 - Periodic Classification of Elements

Name any two elements of group one and write their electronic configurations. What similarity do you observe in their electronic configurations? Write the formula of oxide for any of the above said element.

Answer

1. Two elements of group 1 are: sodium (Na) and Potassium (K).

Electronic configuration of Na: 2, 8, 1

Electronic configuration of K: 2, 8, 8, 1

2. Similarity: they both have 1 electron in the outermost shell .

3. Na/K have a valency of 1 and O has a valency of 2. So the formula of oxide will be Na ₂ O or K ₂ O