Valence Electrons from Periodic Table

[rachelle1K]

How do you tell the number of valence electrons by just looking at the periodic table?

[Cooper Baddley 1F]

The number of valence electrons for an element is equal to its group number starting at one on the left and moving to eight on the far right.

[Astrid Lunde 1I]

To find the valence electron from the periodic table look at the group number.

[KnarGeghamyan1B]

It does correspond to the group but make sure you skip over the transition metals in the middle when looking at elements toward the right. For example, Boron has 3 valence electrons, not 13.

[Ellis Song 4I]

The number of valence electrons is determined by the group number. For groups 13-18, the number of valence electrons is the number in the ones place.

[BCaballero_4F]

You get the number of valence electrons from whatever group the element is in.

[Jessica Li 4F]

I think it's helpful if you have time to write down the electron configuration. Then, you can just count all the subscripts in the highest n level and add them up. This helps prevent confusion with the d orbitals. For instance, for Zinc, the config would be 1s2 2s2 2p6 3s2 3p6 3d10 4s2. Since n =4 is the highest level, and there are only two in the 4s shell, zinc has 2 valence electrons.

[Kristina Rizo 2K]

It does correspond to the group but make sure you skip over the transition metals in the middle when looking at elements toward the right. For example, Boron has 3 valence electrons, not 13.

So we normally skip over the d-block unless stated otherwise? For example, hw problem 2A.1a asks to give the number of valence electrons (including d electrons) for the element Sb. Since it asked to include d-block, the answer would be 15 valence electrons not 5 electrons correct?

[MinuChoi]

For example, hw problem 2A.1a asks to give the number of valence electrons (including d electrons) for the element Sb. Since it asked to include d-block, the answer would be 15 valence electrons not 5 electrons correct?

The valence electrons for Sb would be 5. Keep in mind that the d-block (4d) that is completely full is not in the highest shell (5s25p3). This is why you skip over the transition metal groups when counting nonmetal groups for valence electrons.

[Merin Padayatty 3G]

The number of valence electrons is determined by the group number.

[Leyna Dang 2H]

You can look at the group numbers on the periodic table, but this doesn’t apply to d-block elements. For groups 13-18, the valence electrons correspond to the number that is in the ones place. So oxygen, for instance, is in group 16 so it would have 6 valence electrons.