How Many Valence Electrons Does Carbon (C) Have? [Valency of Carbon]

How Many Valence Electrons Does Carbon (C) Have? [Valency of Carbon]

Carbon, a chemical element with the symbol C and atomic number 6, is a non-metallic element with different appearance means graphite has a black, metallic appearance while diamond has a clear appearance. Carbon has three naturally occurring isotopes: 12C & 13C (stable), and 14C (radioactive).

Carbon is the fourth most abundant element in the universe after hydrogen, helium, and oxygen. Mostly it is found in the form of organic compounds, and with combine with air in the form of carbon dioxide (CO2). The carbon atoms can bond together in diverse forms which result in the formation of different allotropes. Graphite, diamond, and buckminsterfullerene are the best-known allotropes of carbon.

You are here to know valence electrons of carbon atom, aren’t you? Don’t worry along with carbon valence electrons we will explain its valency also. But before that let’s have some basic ideas about what these two terms are:

Difference Between Valence Electrons and Valency

Valence electrons are the total number of electrons present in the outermost shell of an atom (i.e. in outermost orbital). The valence electrons for a neutral atom is always definite, it cannot be varied (more or less) in any condition for a particular atom and may or may not be equal to its valency.

Carbon valence electrons

Valency is defined as the total number of electrons an atom can lose, gain, or share at the time of bond formation to get a stable electronic configuration i.e. to complete an octet. The valency of an atom can be variable in different compounds or chemical reactions due to the different bonding circumstances. Most of the time valency varies/changes due to change in oxidation and reduction states.

Carbon (C) Valence Electrons

There are four simple steps to find out the valence electrons for carbon atom which are:

Step 1: Find the Atomic Number

Carbon valence electrons

To find out the atomic number of carbon, we can use the periodic table. With the help of the periodic table, we can easily see that the atomic number of carbon is 6. As its atomic number is 6, it has six protons, and for neutral carbon, the number of protons are always equal to the number of electrons i.e. has six electrons in its nucleus.

Step 2: Write Electron Configuration

Carbon valence electrons

Electron configuration is the arrangement of electrons on the orbitals. The carbon atom has a total of five electrons so, we have to put 6 electrons in orbitals. The electrons will be placed in different orbitals according to the energy level: [1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f]. Now,

Carbon electron configuration C (6) = 1s2s2p2  (complete configuration).

[He] 2s22p(condensed configuration).

Step3: Determine Valence Shell

As we know, the valence shell of an atom can be found from the highest number of principle quantum numbers which are expressed in the term of n, and in [He] 2s22p2, the highest value of n is 2 so that the valence shell of B is 2s22p2.

Step 4: Find Valence Electrons

The total number of electrons present in the valence shell of an atom are called valence electrons, and there are a total of four electrons present in the valence shell of carbon (2s22p2). Thus, carbon has four valence electrons.

Valency of Carbon (C)

There are many different ways to find out the valency of an atom which reflects the ability of an atom to bond with other atoms. Valence describes how easily an atom or a free radical can combine with other chemical species. The valency of an atom is determined based on the number of electrons lost, gained, or shared with another atom at the time of bond formation.

An atom is said to be stable when its outermost shells have eight electrons (except H & He). If the total number of electrons in outermost shells is between one to four, the atom has positive valency and if electrons are between four to eight, the valency is calculated by subtracting from eight and valency will be zero. Atoms having four outermost electrons possess both positive and negative valency, and atoms having eight outermost electrons, valency will be zero (i.e. noble gases).

Elements like carbon can reach the stable state (nearest inert gas configuration) either by losing 4 outermost electrons or by getting 4 electrons. So that the valency of carbon is 4 (tetravalency).

Note: Carbon has both +4 & -4 valency/oxidation states. If it loses three electrons to reach a stable state (i.e. He), its valency will be +4. But if it gains five electrons to reach a stable state (i.e. Ne), its valency will be -4 as explained above. For example in CO2, the oxidation state of carbon is +4 while in CH4, the oxidation state is -4.

In another sense, a carbon atom can form four covalent bonds in chemical bonding (For example CH4, CCl4, etc.), and that what valency is, the maximum ability to form bonds with different atoms at the time of chemical reactions.

We can also find the valency of carbon with the help of the periodic table. As carbon belongs to group 14 (IVa) along with silicon (Si), germanium (Ge), tin (Sn), lead (Pb), and flerovium (Fl). All these elements have a valency state of four (tetravalent).

Clarification: Valency is the combining capacity of an element at the time of chemical bonding. so that valency cannot be negative or positive, it is just a number value between 0 to 4.

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