How Many Valence Electrons Does Sulfur (S) Have? [Valency of Sulphur]

Sulfur, a chemical element with the symbol S and atomic number 16, is the tenth and fifth-most common element by mass in the universe and on the earth respectively. At normal temperature and pressure sulfur atoms form cyclic octatomic molecule (chemical formula S8).

Sulfur is a very important element in both perspectives: biological and chemical. It is an essential component of all living cells, and is a major component of proteins, enzymes, vitamins, amino acids, cysteine, etc. which show its biological importance.

Elemental sulfur is used as 85% of the production of the king of compounds H2SO4 not only this many majors’ compounds like SO2, H2S are prepared with the help of elemental sulfur which shows its chemical importance.

You are here to know valence electrons of a sulfur atom, aren’t you? Don’t worry along with sulfur 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 are 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.

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.

Sulfur (S) Valence Electrons

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

Step 1: Find the Atomic Number

To find out the atomic number of sulfur, we can use the periodic table. With the help of the periodic table, we can easily see that the atomic number of sulfur is 16. As its atomic number is 16, it has 16 protons, and for neutral sulfur, the number of protons is always equal to the number of electrons i.e. has 16 electrons in its nucleus.

Step 2: Write Electron Configuration

Electron configuration is the arrangement of electrons on the orbitals. The sulfur atom has a total of 16 electrons so, we have to put 16 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,

Sulfur electron configuration S (16) = 1s²2s²2p⁶3s²3p⁴(complete configuration).

= [Ne]3s²3p⁴ (condensed configuration).

Step 3: 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 [Ne]3s²3p⁴, the highest value of n is 3 so that the valence shell of sulfur is 3s²3p⁴.

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 six electrons present in the valence shell of sulfur (3s²3p⁴). Thus, sulfur has six valence electrons.

Also Read:

• Valence Electrons & Valency of Oxygen (O).
• Valence Electrons & Valency of Hydrogen (H).
• Valence Electrons & Valency of Magnesium (Mg). 

Valency of Sulfur (S)

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 sulfur can reach the stable state (nearest inert gas configuration: Ar) by getting 2 electrons. So that the valency of sulfur is 2.

Mathematically, the electronic configuration of sulfur is 2, 8, 6. And as we know, if electrons in outermost shell exceeds from 4, it should be subtracted from 8. So,

Electron Configuration of sulfur (S) = 2, 8, 6

We can see the outer most shell of sulfur has 6 electrons so, have to subtract it from 8.

8 – 6 = 2

That’s why valency of sulfur is 2.

Note: In general, sulfur has a stable oxidation state of -2 in most of the compounds but it varies from -2 to +6 in different compounds due to the different bond stability and formation. Do not confuse with -2 or something else with positive or negative signs, it is just an oxidation number that can vary from compound to compound. But its valency is always 2 in any case.  

In another sense, a sulfur atom can form a maximum of 2 covalent bonds in chemical bonding (For example: CS2, H2S, etc.), and that what valency is, the maximum ability to form bonds with atoms at the time of chemical reactions.

We can also find the valency of sulfur with the help of the periodic table. As sulfur belongs to group 16 (6A or VIA) along with oxygen (O), arsenic (As), and selenium (Se), tellurium (Te), polonium (Po), and livermorium (Lv). These group elements are also called chalcogen. All these elements have a valency of 2.