Question

In which of the following energy of 2s orbital is minimum? 1) Li 2) Na 3) K 4) H

Answer 1

An atomic orbital is a mathematical function in atomic theory and quantum physics that describes the position and wave-like behaviour of an electron in an atom. This function may be used to determine the likelihood of locating any atom's electron in any given location surrounding the nucleus.

Complete step-by-step solution:
When an electron is in the same orbital, a bigger atomic number attracts it more. The energy of the orbital and the electron residing in it diminishes as the attraction increases. Considering the elements in question, a rise in atomic number is in order. The energies of orbitals in the same subshell drop as the atomic number rises. As a result, potassium's 2s orbital (energy level) will have the least energy of all. The energy of orbitals is simply dependent on the primary quantum number in hydrogen, hence the 2s and 2p orbitals have the same energy.
H < Li < Na < K
The ground state in the hydrogen atom corresponds to the most stable situation and is referred to as the 1s orbital, whereas each subsequent orbital has a greater energy than the 1s orbital and is referred to as an excited state. In multi-electron atoms, the energy of orbitals is determined by both the main quantum number (n) or shells and the azimuthal quantum number (l) or subshells. That is, for a given primary quantum number, say 3, the energies of the various subshells 3s, 3p, and 3d will differ.

Note: The existence of reciprocal repulsion among the electrons in multi-electron atoms explains why different energies exist between the various subshells of the same shell. The attractive force between the nucleus and electrons is much stronger than the repulsive forces between electrons in the inner and outer shells, which contributes to the multi-electron atom's stability.