Activity 5.4Look at the group 1 of the Modern Periodic Table, and name the elements present in it.
✅ Answer: Group 1 elements: Hydrogen (H), Lithium (Li), Sodium (Na), Potassium (k), Rubidium (Rb), Cesium (Cs) and Francium (Fr).
Write down the electronic configuration of the first three elements of group 1.
✅ Answer: (i) Hydrogen: 1 (ii) Lithium: 2, 1 (iii) Sodium: 2, 8, 1
What similarity do you find in their electronic configurations?
✅ Answer: They have same number of valence electrons, i.e. 1.
How many valence electrons are present in these three elements?
✅ Answer: 1