Question

If each orbital can hold a maximum of three electrons, then the number of elements in the 9th period of the Modern Periodic Table are?

Answer 1

According to Klechkovski rule

1) Filling the energetic layers with electrons begins from levels with lowest values of n and l and continues in ascending order of n+l total.
2) If n+l total is same for several orbitals, the one with lower n is filled first.

It can be easily shown that in 9-th period next orbitals would be filled: 9s6g7f8d9p.
s-level consists of 1 orbital
p-level consists of 3 orbitals
d-level consists of 5 orbitals
f-level consists of 7 orbitals
g-level consists of 9 orbitals


So we have 1 + 3 + 5 + 7 + 9 = 36 orbitals total. If each orbital can be filled with 3 electrons, then we have 36 ∙ 3 = 108 elements.