Lower energy shell which will be nearer to the nucleus.
Explanation:
When electron move from one energy level to another, an electron must gain or lose just the right amount of energy.
When atoms releases energy, electrons move into lower energy levels. The electrons in the shells aways from the nucleus have more energy as compared to the electrons in the nearer shells.
Electrons with the lowest energy are found closest to the nucleus, where the attractive force of the positively charged nucleus is the greatest. Electrons that have higher energy are found further away
