All elements in period seven (VII) (= 7th row) of the periodic table
There are 73 energy levels in the element tantalum.
The element with atom number seven: NitrogenNitrogen
An element with seven electrons is called nitrogen.
The element rubidium (Rb) as a single atom has thirty-seven protons.
Three: 1s2,2s2, 2p5.
The prefix for seven atoms of the same element is "hepta-". So a molecule with seven atoms of the same element would be described as "heptatomic".
Nitrogen
The period of an element is determined by electronic configuration.Period is same as the number of energy levels of the element.
The atom of an element in the third period of the Periodic Table has 3 energy levels and so on. Also, atoms of elements in the same group have the same no. of valence electrons.
I am not sure about what are the seven levels but check out the site I have attached as a related link you might find your answer there.
Cobalt
Nitrogen