Question

For a hydrogen-like atom, classify the electron transitions according to whether they result in the absorption or emission of light. 

Ignoring sign, which transition is associated with the greatest energy change? 

• n=2 to n=1 

• n =1 to n = 3 

• n =3 to n = 5 

• n =3 to n = 2
  

Answer 1

Answer 2

Concepts and reason

An electronic transition takes place when electrons in a molecule undergo excitation or emission from one energy level to another energy level.

Fundamentals

When an electron is excited from lower energy level to the higher energy level some amount of energy is needed. The process is called as absorption.

When an electron is jumped from higher energy level to the lower energy level some amount of energy will be released. The process is called as emission.

The transition from n=1 to n=3 takes place from lower energy level to the higher energy level. Thus, this transition is absorption.

Electron transition takes place from n=2 to n=1. In the transition, n=1 is lower energy level and n=2 is a higher energy level.

The electronic transition is taking place from n=3 to n=2. The energy level n=2 is lower energy level and n=3 is a higher energy level.

In the transition from n=3 to n=5, n=3 is a lower energy level and n=5 is a higher energy level.

Identify the transition that takes place between the adjacent energy levels and between the far energy levels.

The transition from n=2 to n=1 takes place between the adjacent energy levels. The energy levels in the transition from n=3 to n=2 are also adjacent energy levels.

The energy levels in the transitions from n=1 to n=3 and from n=3 to n=5 are not adjacent energy levels. So these two transitions will have higher energy change. Of these two, n=1 to n=3 will have higher energy change.

Ans:

The transition from n=1 to n=3 is absorption.

The transition from n=2 to n=1 is emission.

The transition from n=3 to n=2 is emission.

The transition from n=3 to n=5 is absorption.

The transition from n=1 to n=3 is associated with greatest energy change.