Finding Valence Electrons

[aphung1E]

How do you determine how many valence electrons an element has using the periodic table?

[Alexis Webb 2B]

The group number is the number of valence electrons.

[Astrid Lunde 1I]

To find the number of valence electrons look at the group number, however this does not work for d block elements.

[Subashni Rajiv 1K]

Another way to remember this is that the noble gases are very stable therefore they have 8 valence electrons, the most stable configuration.

[KaleenaJezycki_1I]

Valence electrons correspond to the elements group #

[Leyna Dang 2H]

The number of valence electrons an element has corresponds with the group/ column it is under on the periodic table. For example, oxygen is in group 6 of the periodic table, therefore it has 6 valence electrons.

Hope this helps!

[Osvaldo SanchezF -1H]

Well the group number can tell you the number of valence electrons except for the D-block of the periodic table, here you actually make an effort in which you can either make the electron configuration to determine the valence electrons or simple see what is its last shell by determining what period it is. You can mathematically figure how many electrons it took to get up to its final shell and just subtract that from the total electrons the element has and that will be the number of valence electrons it has. I believe there is some exceptions though.

[Hailey Kim 4G]

An easy way to find the number of valence electrons an element has is to use the periodic table. The group number (column) represents the number of valence electrons, excluding the transition elements in groups 3-12.
Group 1 = 1 e-
Group 2 = 2 e-
Group 13 = 3 e-
Group 14 = 4 e-
Group 15 = 5 e-
and so on...

[Julia Mazzucato 4D]

If you want to be sure, you can think of the electron configuration for the outermost n level. So for an element where the highest energy level is n=2, you can count the number of electrons in the orbitals starting with 2 (in this case 2s and 2p) to get the VE number.