Some Chem help :/?

The electronic configuration [Xe] 6s²4f⁴ has 6 more electrons than an Xe atom.

The atomic number of Xe, Nd and Pm are 54, 60 and 61 respectively.

If an atom has the electronic configuration [Xe] 6s²4f⁴, the atom is Nd.

If an atom forms a cation carrying 1 positve charge and the electronic configuration of the cation is [Xe] 6s²4f⁴, the atom is Pm.

go to this periodic table
http://www.ptable.com
click on the orbitals tab

mouse to Xe continue to the next element Cs.. note that
.. Xe = 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6
.. Cs = 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s1

so we can abbreviate Cs as
.. Cs = [Xe] 6s1

continuing
.. Ba = [Xe] 6s2
.. La = [Xe] 6s2 5d1
.. Ce = [Xe] 6s2 4f1 5d1
.. Pr = [Xe] 6s2 4f3
.. Nd = [Xe] 6s2 4f4