NTA Abhyas JEE Main2020PhysicsAtomic PhysicsPractice
The radiation corresponding to the transitions of electrons from n = 2 to n = 1 of hydrogen atoms, fall on He + ions which are in n = 1 and n = 2 states. The possible transition of helium ions as they absorb energy from the radiation is
Options
- An = 2 → n = 3
- Bn = 1 → n = 4
- Cn = 2 → n = 5
- Dn = 2 → n = 4
Correct answer
D. n = 2 → n = 4
Step-by-step solution
E = 13 . 6 × 1 × 1 1 2 - 1 2 2 = 10 . 2   eV For He + in n = 2 , 10 . 2   eV = 13 . 6 × 4 1 2 2 - 1 n 2 ⇒ n = 4