What is the spin multiplicity of an electron in the $3d^5$ electronic configuration?

The number of quantum numbers required to describe an electron in an atom completely is

Which of the following explains the sequence of filling the electrons in different shells?

Given,
$(A)$ $n=5, m_l=-1$
$(B)$ $n=3, l=2, m_l=-1, m_s=+\frac{1}{2}$
The maximum number of electron$(s)$ in an atom that can have the quantum numbers as given in $(A)$ and $(B)$ respectively are:

An element has an outermost orbital configuration of $4s^2$. What is its atomic number?

The maximum probability of finding an electron in the $d_{xy}$ orbital is