The maximum number of electrons present in the $N$ shell is:

Which one of the following sets of quantum numbers represents the highest energy level in an atom?

Which of the following is correct for $He$?

The maximum number of electrons in a subshell of an atom is given by ...........

Which of the following statements is not correct for an electron that has the quantum numbers $n = 4$ and $m = 2$?

Given below are two statements. One is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$ : Energy of $2s$ orbital of hydrogen atom is greater than that of $2s$ orbital of lithium.
Reason $R$ : Energies of the orbitals in the same subshell decrease with increase in the atomic number.
In the light of the above statements,choose the correct answer from the options given below.