Question

What is the electron dot diagram for oxygen atom $ ? $

Answer 1

Hint: For drawing the electron dot structure for any element we must know the number of electrons present in its valence shell. This is because we usually represent the valence electrons in the electron dot structure of any element. The number of valence electrons can find out the position of the element in the modern periodic table.

Complete answer:
Electron dot structure is a pictorial representation of the valence electrons present in an element. Since we know that the oxygen atom is present in the $ {16^{th}} $ group of the periodic table. Therefore the number of valence electrons present in oxygen atoms is six. Also we know that the atomic number of oxygen is $ 8 $ and hence its electronic configuration can be written as $ 2,{\text{ 6}} $ . Therefore it contains six valence electrons. Hence its electron dot structure can be shown as,
 $ {\mathbf{:}}\mathop O\limits_{ \bullet \bullet }^{ \bullet \bullet } $
It is not stable as its octet is not complete. Therefore it will form a dimer of it and thus by sharing electrons it will complete its octet and form an oxygen molecule. In an oxygen molecule, both oxygen atoms share two electrons with each other. They share electrons mutually and form covalent bonds. The electron dot structure is sometimes called the Lewis dot structure which shows sharing of electrons to make bonds between the atoms.

Note:
Every element wants to complete its octet and wants to become stable in nature like noble gases. An octet is said to be complete when its outermost shell is completely filled with the electrons according to the rule of $ 2{n^2} $ . Electron dot structure only shows valence electrons of an element.