How do you calculate the number of electrons per shell of an atom of the b groups in your periodic table?

Answer

Dear Tine

Normally the number of electrons per shell is determined by the main quantum number, on each shell 2*n² electrons can take place. This is true for both a and b group elements.

The question will probably be about determining the number of valence electrons. For the a-groups this is their group number.

Determining the number of valence electrons for elements of the b-groups is more difficult … all elements of the same b-group can have the same number of maximum valence electrons, but they can occupy different orbitals (stability rules).

When you want to determine the number of valence electrons of a b-group element; you should actually look at the electron configuration.

The following “rules” do exist:

• Group 3b: 3 valence electrons
• Group 4b: 2 to 4 valence electrons
• Group 5b: 2 to 5 valence electrons
• Group 6b: 2 to 6 valence electrons
• Group 7b: 2 to 7 valence electrons
• Group 8b: 2 or 3 valence electrons
• Group 1b: 1 or 2 valence electrons
• Group 2b: 2 valence electrons