NTA Abhyas JEE Main2020Chemistrys Block ElementsPractice
The first I E 1 and second I E 2 ionization energies (kJ/mol) of a few elements designated by Roman numerals are given below. Which of these would be an alkali metal?
Options
- AI E 1 I E 2 I 2372 5251
- BI E 1 I E 2 II 520 7300
- CI E 1 I E 2 III 900 1760
- DI E 1 I E 2 IV 1680 3380
Correct answer
B. I E 1 I E 2 II 520 7300
Step-by-step solution
As alkali metals have the lowest I E 1 values in their respectively periods and also there is a large jump between I E 1 and I E 2 due to the removal of second electron from the noble gas core, therefore, out of the given I E 1 and I E 2 values (II) belongs to alkali metals.