Valence Electron

[Alexis DeHorta 2A]

Can someone please explain to me how we determine the number of valence electrons per element? I am confused why some elements are able to change the number of electrons that they have, so is there a basic rule for remembering this? For example, I know that Nitrogen would have 5 valence electrons in its outermost shell, but in the homework Nitrogen had 3 valence electrons and was able to bond with 4 hydrogens. Why is this?

[Mikayla 2G]

I determine how many valence electrons elements have by counting how far away the element is from the left side of the table (and skipping over the transition metals). So elements in groups 1 have 1 v e, elements in group 2 have 2 v e, elements in group 13 have 3 v e, elements in group 14 have 4 v e, and so on. The number of electrons will change if the element is an ion. For example, Nitrogen normally has 5 v e, but if it is N^(+) it would only have 4 v e, or N^(2+) it would have 3 v e. I do not think I understand your last question, unless one of the free electron pair from another element became a bond to the N^(2+) ion.

[Clarence Clavite 2K]

So for the first part of your question, the group determines its valence electrons. At least for the s and p suborbital they do. Certain elements are able to change the number of electrons they have through the ionic bonds they create with others. So if a metal were to lose an electron it would become an ion, then it would have changed the number of electrons it has. I am not entirely sure about the rule. As for the nitrogen, it has 5 valence electrons, which means it can form 3 pairs to complete its octet. The structure for NH4 is just an exception. When you work out the formal charges, the nitrogen has a charge of positive 1. This means it's the most stable configuration. Sorry if I missed anything, and hope this helps.

[Monse Mata 3D]

I determine number of valence electrons for an element on the periodic table based on the group number they are under (skipping periods 3-12). So the alkaline earth metals would have two valence electrons and the halogens have eight. However, the number of electrons does change when the element is an ion or cation. For example, Oxygen (O) usually has six valence electrons but if it were O^-it would have seven valence electrons and if it were O^+2 then it would have eight valence electrons.

[Milli Zunich 3I]

You look at groups to tell how many valence electrons an element has. But you should also pay attention to whether it's a cation/anion, which ends up changing the total number of electrons.

[arielle_cunanan3K]

To find the number of valence electrons of the atoms, look at the highest n level , and count how many electrons are in the s and p sub shell for the element.

[Helen Ringley 2E]

Remember that ions can make elements have different amounts of valence electrons, you can't always assume it is a neutral atom.

[Violet Mbela 2B]

Remember that ions can make elements have different amounts of valence electrons, you can't always assume it is a neutral atom.

With ions, a positive indicates that you take away an electron while a negative indicates you adding an electron, right?

[Brenda Tran 3C]

The number of valence electrons can be seen on the periodic table where each column represents the number of valence electrons. The number changes because you are trying to fill up shell so that the molecule is stable. Therefore, with nitrogen is 5 electrons and needs 3 electrons to have a full shell. Therefore, it combines to four hydrogens and has three valence electrons.