h-atom vs multielectron atoms

[Vicky Tong 3E]

Can someone explain why energy levels are different within each subshell for multielectron atoms but not h-atoms? I know something was mentioned about outer electrons being shielded from the attraction, but can someone provide a more in-dept explanation about the h-atoms specifically?

[Marilyn]

What causes the difference in energy levels in other atoms is that there are multiple electrons but hydrogen only has one.

[Crystal Ros 2L]

Hydrogen atoms only have one electron, so in its ground-state, there is no more than one energy level that the electron can rest in. If the electron were excited, then energy would have to be absorbed to excite the electron to a higher energy level. This is one of the points of Bohr's Frequency Condition.

[Nick Smith 2H]

Because Hydrogen only has one electron, there is nothing to counter the attraction of the nucleus resulting in the electron, in any subshell of an energy level, to have the same energy. When we talk about multi-electron atoms, we have to account for electron repulsion. Now, electrons in different subshells push away from each other, causing some subshells to rise to high energy levels and some to fall lower. To sum up the difference, hydrogen does not experience electron repulsion so the only electron is kept under constant attraction from the positively charged nucleus.
Hope this helps!

[Preethika Praveen 2G]

Hi! Hydrogen has only one electron, so there is only force between the negatively charged electron and the positively charged nucleus. However, in a multi-electron atom, there are multiple negatively charged electrons that repel each other. This results in subshells that have different level of energies depending on how close they are to the nucleus. For example, the s subshell is closest to the nucleus and able to shield the other electrons. However, with each increasing subshell type, the electrons are farther from the nucleus, so they are at a higher energy level.