Which of the following transitions would release energy?
n=2–> n=3
n=1 —> n=3
n=3 —> n=1
n=3—> n=2

Answer;

n=3 —>n=1

n=3—>n=2

Explanation;As electron move away from the nucleus, it gains energy and becomes less stable. When electron jumps from lower energy level to higher energy level, it gains energy from surroundings which is known as absorption of energy.Conversely, when an electron jumps from a higher energy level to a lower energy level, it loses or releases energy, which is given out in the form of radiation.Therefore; When an electron absorbs energy, it jumps to a higher orbital. An electron in an excited state can release energy and 'fall' to a lower state.