Show the distribution of electrons

The cation of an element X is represented by ${{X}^{3+}}$. Its atomic number is less than 20. Show the distribution of electrons amongst different orbits of this element. What could this element be?

${{X}^{3+}}$ shows that the element Xhas lost three electrons.
Distribution of electrons amongst different orbits (electronic configuration) of
X = 2,8, 3 or 2, 3.
The given element could be aluminium since, its atomic number is 13 or boron with atomic number is 5.