What are valence electrons?

Valence electrons

The valence electrons are any particles that are loaded in a negative and are essential in the outermost region of atoms which is actively involved in forming the different chemical bonds . Whatever the type of chemical bond, be it ionic , covalent or metallic, that occurs between the atoms, the changes that occur in the atomic structure are restricted to the external or valence electrons . They are more weakly attracted to the positive atomic nucleusthan internal electrons and therefore can be shared or transferred in the bonding process with adjacent atoms . Valence electrons are also involved in conducting electrical current in metals and semiconductors .

What are valence electrons?

They are those that allow the reaction of one atom with another, of the same element or of different elements , since they facilitate the bonds . They are the only ones capable of interacting with electrons from another atom.

  • What are valence electrons
  • What are they for
  • How to remove valence electrons
  • Importance
  • Examples

What are valence electrons

The electron valence electrons are those that are located in the layer outside of an atom and are responsible for conducting the interaction of each element with other to form bonds , and the stability and strength of these. The place where the valence electrons are located corresponds to the last level of the atom. Or rather what would be the orbital more distant .

The bonds that are formed can be ionic , covalent, or orbital overlap . In ionic bonding, the valence electrons are donated by an atom and gained by the atom that has a higher affinity for electrons. In the covalent bond , the valence electrons are neither given nor gained, but instead are shared .

The bonds that form the valence electrons can occur in different ways, either by the exchange of electrons , by sharing pairs between the atoms in question or by the type of interaction that occurs in the metallic bond , which consists of a “Overlap” of bands. Depending on the number of these electrons , it will be the number of bonds that each atom can form with another or others.

What are they for

When atoms form bonds, they only do so through their outermost electrons, those that are located in the last energy level, called valence electrons. The valence electrons are those that allow the reaction of one atom with another to take place, either of the same element or of different elements , since they have the facility or predisposition to participate in the bonds

How to remove valence electrons

For chemists it is very important to know how to find the number of valence electrons for a particular atom, since with this they can determine the chemical bonds that it can form. To be able to do this, you need a periodic table and the following steps:

If a periodic table is used , it can be seen that each vertical column has a number and this belongs to the valence electrons. In case of not having numbered columns, we proceed to assign them a number starting with 1 and ending with number 18.

Valence electrons can be found by looking for the group number of the element to be studied, but for transition metals there is no certain pattern to follow, generally the group number corresponds to a range of possible amounts of electrons. of Valencia, these are:

  • Group 3: 3 valence electrons
  • Group 4: 2 to 4 valence electrons
  • Group 5: 2 to 5
  • Group 6: 2 to 6
  • Group 7: 2 to 7
  • Group 8: 2 or 3
  • Group 9: 2 or 3
  • Group 10: 2 or 3
  • Group 11: 1 or 2
  • Group 12: 2


The valence electrons are of vital importance because they participate in the formation of molecules and compounds since they are in charge of determining the capacity of the atom to be able to form bonds .


Some examples of valence electrons are as follows:

  • Oxygen : it has 6 valence electrons because its electronic configuration is 1s², 2s², 2p⁴
  • Helium:  Helium is a noble gas and therefore it is an element that has no valence, this happens because its last or outer orbits are complete, and for this reason they can form mono atomic molecules and cannot be combined into molecules. Despite this, it can be combined with some heavy noble gases .
  • Calcium : a calcium atom has 2.
  • Beryllium : has 2 in its last layer.
  • Sulfur : it has 18 or 9 pairs.
  • Copper : copper has only 2.
  • Fluorine : has 7.
  • Argon : has 8 in its last level.

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