Maximum number of electrons in a subshell with $l = 3$ and $n = 4$ is

Which of the sequences given below shows the correct increasing order of energy?

What determines the position of an element in the periodic table?

The sum of the number of angular nodes and radial nodes for a $4d$ orbital is:

The quantum number which explains the line spectra observed as doublets in the case of hydrogen and alkali metals, and doublets and triplets in the case of alkaline earth metals is:

What is the difference between $2p_x, 2p_y,$ and $2p_z$ orbitals?