Oxygen Lewis dot structures with itself and other elements can be used for determining chemical bond formation. This article discusses various Oxygen Lewis Dot Structures diagrammatically along with their in-depth explanation.
The atomic number of oxygen is 8 and its electronic configuration is 2,6. This means that an oxygen atom has six electrons in its outermost shell also called a valence shell and to attain the stable 2,8 noble gas configuration (octet) of neon it needs two more electrons. So to achieve that stability one oxygen atom shares its two electrons with the two electrons of another oxygen atom forming a double bond between two oxygen atoms.
As this double bond is formed due to sharing of two-electron pairs, it is called a double covalent bond. The outermost electrons involved in sharing are called shared pairs of electrons and the outermost electrons not involved in sharing are called lone pairs of electrons. Hence a stable oxygen molecule with the formula O2 is formed.
The easiest way of understanding the structural representation and Lewis dot structure which works on any atom, molecule, and compound is given below:
- Count the total number of valence electrons (12 electrons in the case of oxygen molecule, 6 from each oxygen atom).
- Calculate the required electrons (according to octet rule it is 8 in oxygen atom and 16 in oxygen molecule.
- Calculate the bonding electrons (No. of Bonding electrons = Required electrons – Valence electrons, 16 -12 = 4 in the case of oxygen molecule)
- Calculate the number of nonbonding electrons (No. of non-bonding electrons = Valence electrons – Bonding electrons, 12-4 = 8 in the case of oxygen molecule)
Emphasizing these four steps, then the no. of bonding electrons informs you about the presence of a double bond in the above-mentioned case. The number of nonbonding electrons indicates the presence of lone pair electrons. In the above case, there are 8 lone pairs of electrons which when divided by 2 gives the number of electrons per oxygen atom (4). Hence there are 2 lone pairs of electrons.
An interesting fact about the O2 molecule is that it is paramagnetic due to the presence of unpaired electrons. Though this fact cannot be explained by the Oxygen Lewis dot structure and requires a molecular orbital diagram of O2 which is quite complex. Now let us discuss Oxygen Lewis Dot Structure with different elements shown as follows:
Oxygen Lewis dot structure (Ion)
Oxygen ion is represented as O2-. It has a double negative charge attained by gaining 2 electrons. This can be easily explained by the Lewis dot structure. According to the periodic table oxygen (Atomic number=8 and electronic configuration= 2,6) belongs to the 16th group so the oxygen atom has 6 electrons in its valence shell. So to attain stability according to the octet rule it has to gain two electrons and convert into an anion instead of its elemental form. This also emphasizes that oxygen atoms can not only share but gain electrons as well to achieve stability.
Oxygen Lewis dot structure (Atom)
The Lewis structure of the oxygen atom is relatively easier to show as it does not involve any sharing or transference of electrons. The diagram of the oxygen atom shows the valence electron for the element. As oxygen atom (Atomic number = 8 and electronic configuration = 2,6) belong to group 16 in the periodic table, it will be surrounded by 6 valence electrons. But the pairing of valence electrons around the oxygen atom is of significance. Usually, it has each pair of electrons on the two sides and the rest of the two sides have unpaired electrons.
Oxygen Lewis dot structure with Hydrogen
The Lewis dot structure of hydrogen and oxygen results in the formation of water (H2O). Hydrogen atom (Atomic number = 1 and electronic configuration = 1) has one electron in its valence shell. So it requires only one more electron to attain the stable configuration nearest to noble gas Helium. Likewise, oxygen atom (Atomic number = 8 and electronic configuration = 2,6) is scarce of 2 electrons to reach the target octet nearest to noble gas configuration Neon. So in this case each electron of 2 hydrogen atom are mutually shared with 2 valence electrons of a single oxygen atom to form a molecule of water.
Oxygen Lewis dot structure with Lithium
The Lewis dot representation of Lithium and Oxygen shows the formation of Lithium oxide (Li2O). It can be explained visually in a better manner. Each Lithium atom (Atomic number = 3 and electronic configuration = 2,1) loses one valence electron which is simultaneously gained by the Oxygen atom. This leads to Lithium-ion having a +1 charge each which is nearest to noble gas configuration Helium. The charges on Lithium as 2 [Li+] and on oxygen as [O2-] are due to loss of electron and gain of electron respectively.
Oxygen Lewis dot structure with Beryllium
The Lewis dot structure of Beryllium and Oxygen is relatively simple. Beryllium (Atomic number = 4 and electronic configuration = 2,2) belongs to the 2nd group of the periodic table and has 2 valence electrons. Oxygen belongs to the 16th group of the periodic table and has 6 valence electrons. So to attain stability according to the octet rule Beryllium loses its 2 electrons which are gained by oxygen. Likewise, Beryllium changes into a Be2+ cation, and Oxygen changes into O2- anion thereby forming Beryllium oxide (BeO).
Oxygen Lewis dot structure with Carbon
With Carbon and Oxygen, two Lewis dot structures can be formed according to the sharing between electrons to achieve stability. These structures are Carbon dioxide (CO2) and Carbon monoxide (CO).
Emphasizing Carbon dioxide then to complete its octet single carbon atom (Atomic number = 6 and electronic configuration = 2,4) has to bond with 2 oxygen atoms. Carbons have 4 valence electrons and require 4 more electrons and Oxygen has 6 valence electrons and requires 2 more electrons to achieve stability. So there is sharing of electrons between 2 oxygen atoms and a carbon atom which is represented as a double covalent bond.
In the case of Carbon monoxide to gain stability completion of the octet is required between the single carbon atom and an oxygen atom. Here there is sharing of 2 pairs of electrons between carbon and oxygen atoms. To complete octet stability oxygen donate a pair of electron to carbon to a form coordinate bond between carbon and oxygen. This results in the formation of a triple covalent bond.
Oxygen Lewis dot structure with Fluorine (OF2)
The Lewis dot representation of OF2 is not much complex as it involves a single bond. The oxygen atom is in group 16 with 6 valence electrons and the Fluorine atom (Atomic number = 9 and electronic configuration = 2,7) is in group 17 with and has 7 valence electrons. Oxygen being the least electronegative will be present in the centre of 2 fluorine atoms. So there will be sharing of 2 electrons of an oxygen atom with a single electron of each fluorine atom on either side thereby completing the octet for each element.
Oxygen Lewis dot structure with Sodium
Sodium (Atomic number = 11 and electronic configuration = 2,8,11) belongs to the 1st group in the periodic table and needs to lose 1 electron to form Na+ and to gain stable noble gas configuration. On the other side, oxygen belongs to group 16 and needs to gain 2 electrons to complete the octet stability. So each sodium atom loses an electron which is gained by oxygen and results in the formation of Na2O. Here 2[Na+] and [O2-] are held by strong electrostatic forces.
Oxygen Lewis dot structure with Magnesium
Magnesium (Atomic number = 12 and electronic configuration = 2,8,2) belong to the 2nd group in the periodic table and need to lose 2 electrons to attain stability. On the flip side, oxygen gains those 2 electrons to complete its octet. So Mg2+ and O2- being equally and oppositely charged get attracted to each other and form MgO which is held together by strong electrostatic forces.
Oxygen Lewis dot structure with Aluminium
The structure formed between Aluminium (Atomic number = 13 and electronic configuration = 2,8,3) and oxygen is aluminium oxide (Al2O3). Al2O3 is an ionic compound which means there is the transference of electrons between aluminium and oxygen. So aluminium belongs to group 13 in the periodic table and has 3 valence electrons and oxygen belongs to group 16 and has 6 electrons. Aluminium being less electronegative will donate its 3 electrons and oxygen being more electronegative will gain it. Hence the 2 aluminium atoms will convert into 2[Al3+} cation and 3 oxygen atoms will convert into 3[O2-] anions.
Oxygen Lewis dot structure with Silicon
It results in the formation of SiO2. Silicon (Atomic number = 14 and electronic configuration = 2,8,4) has 4 valence electrons and oxygen has 6 valence electrons. So to complete their octet 2 atoms of oxygen will share their electrons with a single silicon atom. There will be a double covalent bond formation.
Oxygen Lewis dot structure with Chlorine (OCl2)
Chlorine (Atomic number = 17 and electronic configuration = 2,8,7) belongs to group 17 of the periodic table and needs 1 electron to complete its stable noble gas configuration. Oxygen on the other hand belongs to group 16 and is scarce of 2 electrons to achieve the noble gas configuration. So oxygen will become the central atom and will share each electron from two chlorine atoms. This leads to the formation of OCl2 where a single covalent bond formation is there between participating atoms
Oxygen Lewis dot structure with Potassium
The lewis dot structure of Potassium (Atomic number 19 and electronic configuration = 2,8,8,1) is on the same line as that of sodium and oxygen. Potassium belongs to group 1 of the periodic table and to achieve stability it has to lose 1 electron. Oxygen on the other hand needs to gain 2 electrons to complete its stability. So each potassium atom donates 1 electron to oxygen and results in ionic compound K2O and the ions are held together by strong electrostatic forces.
Oxygen Lewis dot structure with Calcium
Calcium (Atomic number = 20 and electronic configuration = 2,8,8,2) loses 2 electrons to attain stability and oxygen as mentioned several times need to gain 2 electrons to attain stability. Now due to this transference of electrons calcium and oxygen will become opposite charged and form ionic compound CaO
Oxygen Lewis dot Structure (Related FAQs)
Properties explained by Oxygen Lewis dot structure
Oxygen Lewis’s structure is perfectly symmetric and is nonpolar. Also, nonpolar molecules are usually gases in nature hence there is not much difference in dioxygen molecule and oxygen gas
Role of outermost electrons in Oxygen Lewis dot structure
The outermost electrons are called valence electrons. They are responsible for chemical bond formation and reaction because they are loosely bound to the nucleus. Due to less nuclear binding force, they can easily participate in sharing and transference of electrons. On the other hand, as we move from valence electrons towards inner electrons the nuclear binding increases making it difficult for them to participate in any bond formation and reaction.
Difference in Lewis dot structure and molecular structure
Lewis Structures represent the movement and presence of electrons in a compound according to its stability factor. It shows the number of atoms, valence electrons, and bonds readily. However molecular shapes of compounds are influenced by various forces among atoms and depend on bond angles and bond lengths