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How many pairs of electrons do the two oxygen atoms in an oxygen molecule share with...

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lizzyabeth100 | Student, Grade 9 | eNotes Newbie

Posted September 28, 2009 at 11:47 AM via web

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How many pairs of electrons do the two oxygen atoms in an oxygen molecule share with each other? Please explain.

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krishna-agrawala | College Teacher | (Level 3) Valedictorian

Posted September 28, 2009 at 12:51 PM (Answer #1)

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Oxygen is an element with the chemical formula O. An oxygen atom has atomic number 8, and gas total of 8 electron in each atom. An oxygen molecule has two atoms in it. Another form of oxygen called ozone has three atoms in a molecule.

An oxygen atom has 8 electron arranges in two shells. The inner shell has 2 electron and the outer shell, called valance shell has 6 electrons. To achieve stability the valence shell needs 8 electron in it. Therefore, in an oxygen molecule 2 pairs of electron in the valence shell are shared by by the two atoms. This makes the number of electron in outer shell of each atom equal to 8.

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neela | High School Teacher | (Level 3) Valedictorian

Posted September 28, 2009 at 1:02 PM (Answer #2)

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Oxygen molecule has a pair of oxygen atoms. So,the oxygen molecule is represented by the formula O2.

The oxygen atom has  8 elctrons. In the first K shell it has 2 electrons and in the L shell it has 6 electrons.

The electronic configuration of the oxygen atom  is :

 1s2  2s2 2p4.

In the outer Lshell there are 6 electrons (short of 2 electrons compared to noble gases).So if we pair the electrons,it require two more eletrons .So this could be made good by capturing 2 electrons or sharing with 2electrons.Therefore, two electrons of each of the atom in the oxygen molecule makes the double bond with each other to attain the stable configuration of noble gas.

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ebaker13 | High School Teacher | (Level 1) Adjunct Educator

Posted September 29, 2009 at 1:01 AM (Answer #3)

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Two oxygen atoms in a oxygen molecule share two electrons.  Oxygen atoms only have 6 valence electrons (electrons in the outer shell).  They want 8 electrons so they need to steal two or share two. 

It is easier for two oxygen molecules to share their electrons then to find two atoms to steal one from or find one atom to steal two from.  The two oxygen atoms share two electrons so that they each have 8 electrons in their outer shell and are therefore full.

They are bonded together with a covalent bond.  A covalent bond is a strong bond when two atoms are sharing outer electrons. 

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