All electrons in the $4p$ sub-shell must be characterized by which of the following quantum numbers?

Given below are the quantum numbers for $4$ electrons.
$A. \; n = 3, l = 2, m_l = 1, m_s = +1/2$
$B. \; n = 4, l = 1, m_l = 0, m_s = +1/2$
$C. \; n = 4, l = 2, m_l = -2, m_s = -1/2$
$D. \; n = 3, l = 1, m_l = -1, m_s = +1/2$
The correct order of increasing energy is

What is the difference between $2p$ and $2s$ orbitals?

Considering the ground state of $Cr$ atom $(Z = 24)$,the number of electrons associated with azimuthal quantum numbers $l = 1$ and $l = 2$ are,respectively:

Arrange the following atomic orbitals of multi-electron atoms in order of increasing energy.
$A$. $n=3, l=2, m=+1$
$B$. $n=4, l=0, m=0$
$C$. $n=6, l=1, m=0$
$D$. $n=5, l=1, m=+1$
$E$. $n=2, l=1, m=+1$
Choose the correct answer from the options given below:

An ion with a charge of $-2$ has the electronic configuration $1s^2, 2s^2, 2p^6$. Identify the ion.