Question

You have learned that each orbital is allowed two electrons, and this pattern is evident on the periodic table. What if each orbital was allowed three electrons? How would this change the appearance of the periodic table? For example, what would be the atomic numbers of the noble gases?

Short answer

If each orbital was allowed 3 electrons instead of 2, the periodic table would be 9 groups wider. The atomic numbers of the noble gases would be 3, 15, 27, 54, and 81 respectively.

Step-by-step solution

Describing the appearance of the periodic table if each orbital was allowed 3 electrons

If each orbital was allowed 3 electrons instead of 2, the periodic table would be wider.

• The S block would be 3 groups wider

• The P block would be 9 groups wider

• The D block would be 5 groups wider.

In all, the periodic table would be 9 groups wider.

Determining the atomic numbers of the noble gases if each orbital was allowed 3 electrons

In this case, the configuration would become 1s³2s³2p⁹……

By the calculation, the atomic number of the noble gases would become,

Helium = 3

Neon = 15

Argon = 27

Krypton = 54

Xenon = 81