Among the following systems, which will have the minimum radius for the first orbit ( n = 1 )?

Step-by-step solution

The radius of the n -th Bohr orbit for a hydrogen-like species is given by: r_n = 0.529 n^2 Z For the first orbit, n = 1 . Thus, the radius is inversely proportional to the atomic number Z ( r₁ 1 Z ). To have the minimum radius, the system must have the maximum atomic number Z . For doubly ionized lithium ( Li²⁺ ), Z = 3 For deuterium atom ( D ), Z = 1 For singly ionized helium ( He^+ ), Z = 2 For hydrogen atom ( H ), Z = 1 Since Li²⁺ has the highest atomic number ( Z = 3 ), it will have the minimum radius for the