Which element is represented by the following electronic configuration?

Total number of electrons in $Cu$ atom having $m_l = 0$.

Find the number of unpaired electrons for copper in ground state configuration.

The correct order of increasing energy of atomic orbitals is

$A$: The energy of an electron can be determined by the principal quantum number.
$R$: The principal quantum number $(n)$ determines the possible distance of the electron from the nucleus.

For $p$-orbital,the magnetic quantum number has value