Question

why the shell closer to nucieus have lower energy than shell away from it?

Answer 1

The nucleus is positively charged (because of the protons) and electrons are negatively charged. Imagine a proton and an electron right next to each other. Now start to separate them apart. THis takes energy because the proton and electron have an attractive force that you have to overcome. The further away you separate them the more energy you need to do so. And so it is with the energy shells

Answer 2

if i am not taking electrons away then also there is energy difference
for taking electrons a little distance apart more energy is required as attraction is more so energy shoud be higher than why low?

Answer 3

Are you talking about the ability to gain an electron? If so the electron affinity is probably higher due to a smaller ionic radius.

Answer 4

no. i am asking when attraction more, why more energy and which

Answer 5

why less energy not more?

Answer 6

Same speed but less distance traveled = less energy. it takes less energy to drive around the block than it does to drive around the outskirts of a city.

Answer 7

Ok so you're saying when you bring an electron closer to the nucleus why does it need more energy? Because there's a force repelling the protons in the nucleus from the electrons.

Answer 8

Are you asking about the way energy levels in an atom are expressed? Like when some texts will say the energy of the electron in a hydrogen atom is -13.6 eV ? In that case they are referring to the binding energy of the electron, ie, how much energy it would take to kick it out into free space and ionize the atom. It takes 13.6 eV to ionize hydrogen. So the shell closer to the nucleus has a 'lower energy' than the shell further away because it takes more energy to pull an electron away when its closer to the nucleus. Consider some theoretical atom that has two energy levels. Say the closer energy level (shell) is at -13.6 eV, and the further one is -4 eV. The one that is closer has a lower number, but that actually means it takes more energy to bump it from the atom because it is in a more stable shell. Is this what you're asking about?

Answer 9

this question has been more or less answered already, but i have another way to think about it.

an electron it its negative charge is attracted to a proton with its positive charge. when left alone, the electron feels a force from the proton in the direction of the proton (in other words, this force pushes the electron towards the proton). someone or something could use this force to do work, like pushing a very small cart up a hill. if that albeit fictional story were to occur, the cart would be gaining energy as it goes up the hill, and that energy would have to come from the force that was acting on the electron.

since the energy in the cart increases, and must come from somewhere, that means that the electron that is pushing the cart must be losing energy. that is one way of looking at why electrons that are closer to the nucleus have a lower energy than electrons farther away.