Expert Answers
jerichorayel eNotes educator| Certified Educator

Valence electrons are the electrons in the last energy shell or the outermost shell on the atom. These electrons are the ones that participate in the chemical reactions. We can determine the valence electrons based on their position on the periodic table. The following are some examples of atoms with their respective valence electrons:

Na = 1

Mg = 2

Al = 3

C = 4

N = 5

O = 6


This is generally applied in s and p groups in the periodic table. Elements in the transition metals (d group) sometimes can have valence electrons available in their inner shell. 


Further Reading:
suzannah304 | Student

Valence elecrons are the electrons in the outermost shell (energy level)of an atom. Valence electrons participate in forming chemical bonds with other atoms.

vanshsodhi | Student


Valence electrons are the electrons(or the negatively charged subatomic particles)found in the outermost orbit(or energy level or shell)of an atom.It is the valence electrons which decide the chemical properties of an element since it is these electrons which take part in a chemical reaction.They also determine the valency of an element.

For example-Na has 1 valence electron, hence its valency is one(as it tnds to donate the single electron).

kavya--kammana | Student

valence electrons are electrons found in the outermost shell or orbit of the atom of an element.

eg : oxygen 

      its electronic configuration is 2,6 . so there are two shells.

      no. of electrons in outermost shell is 6

      valence electrons = 6