The maximum number of electrons that can be accommodated in a $3d$ subshell is

The principle which states that electron occupies the available orbitals singly before pairing in any one orbital occurs is known as:

The quantum numbers of six electrons are given below. Arrange them in order of increasing energy. If any of these combinations have the same energy,list them:
$(1)$ $n = 4, l = 2, m_l = 2, m_s = -1/2$
$(2)$ $n = 3, l = 2, m_l = 1, m_s = +1/2$
$(3)$ $n = 4, l = 1, m_l = 0, m_s = +1/2$
$(4)$ $n = 3, l = 2, m_l = -2, m_s = -1/2$
$(5)$ $n = 3, l = 1, m_l = -1, m_s = +1/2$
$(6)$ $n = 4, l = 1, m_l = 0, m_s = +1/2$

Which of the following electronic configurations has the maximum energy?

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

What are the values of $n$ and $l$ for the $f$-subshell with the lowest energy?