$1s^2 2s^2 2p^6 3s^2$ is the electronic configuration of the metal

For an electron with $n = 3$,there is only one radial node. The orbital angular momentum of the electron will be

When the $3d$ orbital is completely filled,the next entering electron will be in the ....... orbital.

The quantum numbers $n = 2, l = 1$ represent:

For a $4p$-orbital,the number of radial and angular nodes,respectively,are

Statement $1$: The energy of an electron is determined by the principal quantum number.
Statement $2$: The principal quantum number $(n)$ indicates the distance of the electron from the nucleus.