Number Of Valence Electrons In Chlorine

  1. Valence Electrons Chart
  2. Total Number Of Valence Electrons In Chlorine
  3. The Number Of Valence Electrons In Chlorine

Lewis structure of ClO4- ion is drawn step by step in this tutorial. Total valence electrons of given by four oxygen atoms,chlorine atom and negative charge are considered to draw the ClO4- lewis structure.

The electronic configuration of chlorine is, Cl (Z= 17) = 1s2 2s2 2p6 3s2 3p5 Hence, it has 2 electrons in its inner-most shell, 8 electrons in its second shell and 7 electrons in the outer-most shell respectively. ∴ There are 7 valence electrons in the chlorine atom. Well, there's two and five, for a total of seven. So chlorine has seven valence electrons. And once again, that's very convenient, because chlorine is in group seven. And so let's go ahead and draw chlorine with its seven valence electrons. Chlorine: Atomic Number = 17. Atomic Mass = 35.453. Amount of Protons = 17. Amount of Neutrons = 18. Amount of Electrons = 17. Therefore your answer is option A '17.' You can find the number of electrons by looking at the elements atomic number which is equal to the amount of protons the element has then the protons is equal to the amount the electrons it has so. Valence electrons are the number of electrons present in the outermost shell of an atom. The last shell of a chlorine atom has 7 electrons in it. Therefore, there are 7 valence electrons in an chlorine atom. Here is a video which gives a quick discussion of how to determine how many valence electrons atoms of different elements have.

Lewis Structure of perchlorate ion

There are four oxygen atoms and chlorine atom in perchlorate ion.

Now, we are going to learn, how to draw the lewis structure of ClO4- ion step by step. You will learn all steps and rules of lewis structure drawing.

Chlorine: Atomic Number = 17. Atomic Mass = 35.453. Amount of Protons = 17. Amount of Neutrons = 18. Amount of Electrons = 17. Therefore your answer is option A '17.' You can find the number of electrons by looking at the elements atomic number which is equal to the amount of protons the element has then the protons is equal to the amount the electrons it has so.

Steps of drawing ClO4- lewis structure

Following steps are required to draw ClO3- lewis structure and they are explained in detail in this tutorial.

  1. How to find total number of electrons of the valance shells of chlorine and oxygen atoms and including charge of the anion
  2. How many electrons pairs in valence shells
  3. Determine center atom from chlorine and oxygen atom
  4. Put lone pairs on atoms
  5. Stability of lewis structure - Check the stability and minimize charges on atoms by converting lone pairs to bonds to obtain the best lewis structure.

Drawing correct lewis structure is important to draw resonance structures of ClO4- ion.

Total number of electrons of the valance shells of chlorine and oxygen atoms and charge of the anion

There are one chlorine atom and four oxygen atoms in the chlorate ion. Also there is a -1 overall charge on the ClO3- ion.

Chlorine and oxygen are located at 7 and 6 groups respectively in the periodic table. So chlorine has seven electrons in its valence shell and for oxygen atom, there are six electrons in its valence shell.

  • Total valence electrons given by chlorine atoms = 7*1 = 7

There are three oxygen atoms in ClO4- ion, Therefore

  • Total valence electrons given by oxygen atoms = 6 * 4 = 24

Due to -1 charge, another electrons is added

  • Due to -1 charge, received electrons to valence electrons= 1

  • Total valence electrons = 7 + 24 + 1 = 32

Total valence electrons pairs

Total valance electrons pairs = σ bonds + π bonds + lone pairs at valence shells

Total electron pairs are determined by dividing the number total valence electrons by two. For, ClO4- there are 32 valence electrons, so total pairs of electrons are 16. In next steps, we are going to mark those 16 lone pairs on oxygen atoms and chlorine atoms as bonds and lone pairs.

Center atom of ClO4- ion

To be the center atom, ability of having greater valance is important. Chlorine can show valence 7. But, oxygen's maximum valence is 2. Therefore chlorine has more chance to be the center atom (See the figure). So, now we can build a sketch of ClO4- ion.

Sketch of ClO4- ion

Lone pairs on atoms

  • There are already four Cl-O bonds in the sketch. Therefore only twelve valence electrons pairs are remaining to draw the rest of ion.
  • Next step is, marking those ten valence electrons pairs on outside atoms (in this case, oxygen atoms) as lone pairs. One oxygen atom will take three lone pairs following the octal rule (oxygen atoms cannot keep more than eight electrons in their valence shells). Therefore, twelve electrons pairs are marked on three oxygen atoms. Now, all electrons pairs are finished due to marking on oxygen atoms.
  • So, there is no valence electrons pair to mark on chlorine atom.

Check the stability of drawn structure of ClO4- ion and reduce charges on atoms by converting lone pairs to bonds

Check charges on atoms and mark them as below. Charges are important to decide the best lewis structure of the ion because in the best lewis structure, charges should be minimized.

The drawn structure for ClO4- is not a stable structure because oxygen atoms and chlorine atoms have charges. Also, when charge of an atom (in chlorine atom, there is a +3 charge) is large, that structure become more unstable and cannot be a good lewis structure. When a molecule or ion has so many charges on atoms, that structure is not stable. Now, we should try to find a more stable structure.

Now, we should try to minimize charges by converting lone pair or pairs which exist on oxygen atoms to bonds. So we convert one lone pair of one oxygen atom as a Cl-O bond as in the following figure.

Now there is a double bond between chlorine and one oxygen atom. There are also three single bonds (Cl-O) with chlorine atom and other two oxygen atoms.

But, there are still charges on atoms and given structure is not stable yet. If possible, we should reduce charges furthermore. Another lone pair on another oxygen atom is transferred as a Cl-O bond.

Now, there are twelve electrons around chlorine atom. This is acceptable because chlorine can keep more than eight electrons chlorine has unfilled 3d orbits.

In new structure, charges of atoms are reduced furthermore. But, we can convert one more lone pair on another oxygen atom to make an another double bond. Now you understand this structure of ClO4- is more stable than previous structure due to less charges on atoms.


ClO4- Lewis structure

Questions asked by students

Ask your question and find the answer free.

how many lone pairs are found in the lewis structure for the perchlorate ion, ClO4--?

In last shells, there are nine lone pairs on atoms. There are three oxygen atoms which are connected through double bonds to chlorine atom. Each of those oxygen atoms have two lone pairs. Remaining oxygen atom has three lone pairs and ceenter atom, chlorine does not has lone pairs.


What is the charge of ClO4-

Charge of ClO4- ion is -1. This -1 negative charge is located at an oxygen atom.

ClO4-lewis structure molecular geometry

Around chlorine atom, there are four σ bonds zero lone pairs. Therefore shape of the anion around chlorine atom is tetrahedral.

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Chloromethane or Methyl chloride having a molecular formula of CH3Cl is an organic compound. It is an odorless and transparent gas that was initially used as a refrigerant. Later it was found that this gas is toxic and can harm the central nervous system of humans. Although it is no longer used as a refrigerant, Chloromethane has many uses and applications in several chemical and pharmaceutical industries.

To understand its chemical properties and physical properties, one needs first to know the Lewis structure and molecular geometry of CH3Cl. And to help you with understanding its structure in-depth, I will help you to make its Lewis structure step-by-step in this blog post.

But before looking at that, let us first discuss the valence electrons present in this compound as these electrons are the ones that form bonds.

CH3Cl Valence electrons

If you have been studying chemistry for some time, then you might be aware of the “octet rule.” This rule states that atoms bond with each other atoms such that they have eight electrons in the last valence shell. This happens because it tries to achieve the same valence electron configuration as inert gases. The atoms that have complete octets or rather suffice the octet rule become inert and non-reactive. There are some exceptions to this octet rule, e.g., Hydrogen.

These valence electrons are the ones that participate in the bond formation. So let us have a look at the total number of valence electrons for CH3Cl.

Total no of valence electrons of CH3Cl = Valence electrons of Carbon + Valence electrons of Hydrogen + Valence electrons of Chlorine

Valence electrons of Carbon: 4 electrons

Valence electrons of Hydrogen: 1 * 3 = 3 electrons ( as there are three hydrogen atoms, we will consider valence electrons of all the Hydrogen atoms )

Valence electrons of Chlorine: 7 valence electrons

Total no of valence electrons of CH3Cl= 4 + 3 +7


Chloromethane ( CH3Cl) has 14 valence electrons.

CH3Cl Lewis structure

Now that we know the total number of valence electrons in CH3Cl, we can now draw a Lewis structure for the same. This structure helps understand the arrangement of valence electrons around the individual atoms along with the bonds they form. In Lewis structure, we use dots to represent electrons and lines to show bonds formed between two atoms.

Here we have three types of atoms in CH3Cl: Carbon, Hydrogen, and Chlorine. Out of all these atoms, Carbon is the least electronegative one, and hence we will place it in the central position. Chlorine is the most electronegative atom.

So place the Carbon atom in the center and draw four dots around it like this: Apple update high sierra download.

Now that we have placed the Carbon atom, let’s put other atoms. As there are three hydrogen atoms, we will first put these atoms around the Carbon atom. Place three H atoms with one dot around the central atom.

As we have already place carbon and Hydrogen atoms, we just have to place a Chlorine atom in this structure. Place it on the forth side of the Carbon atom like this

Now, if you see closely, the Carbon atom is sharing four electrons with three hydrogen atoms and a Chlorine atom. As the Carbon atom needs 4 electrons to complete its octet, all the valency is satisfied, and it now has eight electrons in its valence shell.

Valence Electrons Chart

Similarly, each Hydrogen atom needs one electron, which they share with the central Carbon atom, and hence their outer shell is also completed. Due to their sharing of electrons, there is a single bond between C and H atoms.

In contrast, the Chlorine atom also completes its octet as it shares an electron with the Carbon atom. Carbon and Chlorine form a single bond as they share one electron to complete each other’s octet. Hence all the valence electrons are used up, and there are four single bonds in the Lewis structure of CH3Cl.

CH3Cl Hybridization

One can find the hybridization of any given molecule by using this simple formula:

Total Number Of Valence Electrons In Chlorine

Hybridization = No. of bonds + lone pairs at the central atom

= 4 + 0 ( there are no lone pairs in CH3Cl as there is symmetric distribution of electrons)


The carbon atom has an electronic configuration of 1s22s22p2 in its ground state and has when it is in an excited state; the configuration is 1s22s12p3. Here the electrons shared by the Carbon lead to the formation of four hybridized orbitals, which include one s-orbital and three p-orbitals. All the four electrons are arranged in these hybridized orbitals, making the hybridization of this molecule sp3.

The Number Of Valence Electrons In Chlorine

CH3Cl Molecular Geometry

The molecular geometry of any given molecule is based on the number of atoms involved and the bonds formed in the structure. VSEPR theory or Valence electron shall pair repulsion theory is the concept we use to determine the molecule’s shape. This theory states that a molecule takes a shape in which two negatively charged centers are as far from each other as possible ( both bonded and non-bonded pairs of electrons). The theory states that this happens to avoid repulsive forces. According to the VSEPR theory, molecules having a structure similar to AX4, where a molecule has four negatively charged centers, will take a tetrahedral shape.

Also, it has bond angles of 109.5, which corresponds to its molecular geometry. Hence, Chloromethane has a tetrahedral molecular geometry to avoid the repulsive forces and separating the bonded electrons.

Concluding Remarks

To summarize, we can say the following for a single molecule of Chloromethane.

  • It has 14 valence electrons, and all of them participate in forming bonds.
  • In the Lewis structure of CH3Cl, Carbon is at the central position and all the other atoms around it.
  • The bond angles of Carbon with Hydrogen and Chlorine atoms are 109.5 degrees.
  • This molecule has a tetrahedral shape, and the central carbon atom has sp3 hybridization.