Highly selective Backlog Qs for JEE MainChemistryClassification of Elements and Periodicity in Properties
Correct order of radius of the first orbit of H ,   He + ,   Li 2 + ,   Be 3 + is:
Options
- AH > He + > Li 2 + > Be 3 +
- BBe 3 + > Li 2 + > He + > H
- CHe + > Be 3 + > Li 2 + > H
- DHe + > H > Li 2 + > Be 3 +
Correct answer
A. H > He + > Li 2 + > Be 3 +
Step-by-step solution
rα n 2 Z , as Z increases, the radius of 1 st orbit decreases. Alternatively, higher charge lower radii in the same period or number of proton increases, the size decreases.