Question What is valence/valency simplified?

Mar 4, 2020
Valence is most often a chemistry term or an electronic term, used to denote an ionization potential.

That's a fancy way of saying that how easily an electron can leave or enter a nucleus.

The term valence also has meanings in lots of other fields of study too. Depending on the field of study and the influence of valence on that field........valence has several narratives for this potential.

In other words, the property or the concept and sense of valence, depends on what field of study that you are relating valence to.

The true physical dynamic of ionization, and the potential for it, is unknown. This is because the structure of the elements, and the component structures that form elements remains unknown.

We know that an element or an atom can lose or gain electrons, giving the atom a net charge. We also know that ionization causes a change in the physical size of the atom too. We also know that some atoms(which infers that some structures) have more of a valence potential than other atoms(structures).

We also know that this potential has a great affect on what elements can bind......under all kinds of environments and other external influences.

But the actual mechanism of ionization remains unknown, because we do not know what mass is. If knowing that an electron is exchanged/shared is all that is needed, then valence of mass/matter is accepted as a known property. But the physical structure of an electron and a nucleus remains unknown. So we have no idea of the true physical bond.

Valence describes an atomic property that can be measured, but the cause remains unknown. We have several narratives for it, but the mysteries of mass and matter persist to this day. No one knows what mass is. We only know how it reacts to stimulus. We have no clue as to WHY is reacts as it does. We need to know the structure and motion of the sub atomic components, in order to find out what this stuff is.

But all we can detect and measure is a blur, a fuzz sphere. The cause of all the fundamental properties remains unknown. We are still completely ignorant of mass and matter.

Whatever field you decide to study and work with, you will need to accept and work with the narrative about valence, for that field.

In chemistry it's a binding potential which requires an energy exchange. Some bindings require a energy release and some bindings require an energy absorption.

In electronics it's an electrical potential that's required for current or emission. Other fields have their own sense of reference.

My comments are general and simplified, for a more specific definition, you need to refer to the particular field of study of interest. For the selectable context of the concept.

Until we discern what mass is, all concepts will remain confusing.

I for one believe that all physical properties, come from motional structure.
Vaence - noun
  1. Also va·len·cy [vey-luhn-see] .Chemistry.
    • the quality that determines the number of atoms or groups with which any single atom or group will unite chemically.
    • the relative combining capacity of an atom or group compared with that of the standard hydrogen atom. The chloride ion, Cl–, with a valence of one, has the capacity to unite with one atom of hydrogen or its equivalent, as in HCl or NaCl.
  2. Immunology. the number of determinants per molecule of antigen.
  3. the capacity of one person or thing to react with or affect another in some special way, as by attraction or the facilitation of a function or activity.

An element's electron cloud will become more stable by filling, emptying, or half-filling the shell. Also, shells don't stack neatly one on top of another, so don't always assume an element's valence is determined by the number of electrons in its outer shell.

The valences of the elements—the number of electrons with which an atom will bond or form—are those that can be derived by looking at the groups (columns) of the periodic table. While these are the most common valences, the real behavior of electrons is less simple.

Number Element Valence
1Hydrogen(-1), +1
5Boron-3, +3
6Carbon(+2), +4
7Nitrogen-3, -2, -1, (+1), +2, +3, +4, +5
9Fluorine-1, (+1)
14Silicon-4, (+2), +4
15Phosphorus-3, +1, +3, +5
16Sulfur-2, +2, +4, +6
17Chlorine-1, +1, (+2), +3, (+4), +5, +7
22Titanium+2, +3, +4
23Vanadium+2, +3, +4, +5
24Chromium+2, +3, +6
25Manganese+2, (+3), +4, (+6), +7
26Iron+2, +3, (+4), (+6)
27Cobalt+2, +3, (+4)
28Nickel(+1), +2, (+3), (+4)
29Copper+1, +2, (+3)
31Gallium(+2). +3
32Germanium-4, +2, +4
33Arsenic-3, (+2), +3, +5
34Selenium-2, (+2), +4, +6
35Bromine-1, +1, (+3), (+4), +5
40Zirconium(+2), (+3), +4
41Niobium(+2), +3, (+4), +5
42Molybdenum(+2), +3, (+4), (+5), +6
44Ruthenium(+2), +3, +4, (+6), (+7), +8
45Rhodium(+2), (+3), +4, (+6)
46Palladium+2, +4, (+6)
47Silver+1, (+2), (+3)
48Cadmium(+1), +2
49Indium(+1), (+2), +3
50Tin+2, +4
51Antimony-3, +3, (+4), +5
52Tellurium-2, (+2), +4, +6
53Iodine-1, +1, (+3), (+4), +5, +7
58Cerium+3, +4
60Neodymium+3, +4
62Samarium(+2), +3
63Europium(+2), +3
65Terbium+3, +4
69Thulium(+2), +3
70Ytterbium(+2), +3
73Tantalum(+3), (+4), +5
74Tungsten(+2), (+3), (+4), (+5), +6
75Rhenium(-1), (+1), +2, (+3), +4, (+5), +6, +7
76Osmium(+2), +3, +4, +6, +8
77Iridium(+1), (+2), +3, +4, +6
78Platinum(+1), +2, (+3), +4, +6
79Gold+1, (+2), +3
80Mercury+1, +2
81Thallium+1, (+2), +3
82Lead+2, +4
83Bismuth(-3), (+2), +3, (+4), (+5)
84Polonium(-2), +2, +4, (+6)
92Uranium(+2), +3, +4, (+5), +6

  • Brown, I. David. "The Chemical Bond in Inorganic Chemistry: The Bond Valence Model," 2nd ed. International Union of Crystallography. Oxford: Oxford Science Publications, 2016.
  • Lange, Norbert A. "Lange's Handbook of Chemistry," 8th ed. Handbook Publishers, 1952.
  • O'Dwyer, M.F., J.E. Kent, and R. D. Brown. "Valency." New York: Springer-Verlag, 1978.
  • Smart, Lesley E. and Elaine A. Moore. "Solid State Chemistry An Introduction," 4th edition. Boca Raton: CRC Press, 2016.
The first great step in the development of a satisfactory explanation of valence and chemical combination was made by the American chemist G.N. Lewis (1916) with the identification of the chemical bond of organic compounds with a pair of electrons held jointly by two atoms and serving to hold them together. In the same year, the nature of the chemical bond between electrically charged atoms (ions) was discussed by German physicist W. Kossel. After the development of the detailed electronic theory of the periodic system of the elements, the theory of valence was reformulated in terms of electronic structures and interatomic forces. This situation led to the introduction of several new concepts—ionic valence, covalence, oxidation number, coordination number, metallic valence—corresponding to different modes of interaction of atoms.


Valence electrons are the electrons in the outermost shell, or energy level, of an atom. For example, oxygen has six valence electrons, two in the 2s sub-shell and four in the 2p sub-shell. We can write the configuration of oxygen's valence electrons as 2s²2p⁴.