Question
Explain the following terms with example: Covalent bond.
✓
Answer
The chemical bond formed by sharing of two valence electrons between the two atoms is called covalent bond.
Example:
$1.$ Hydrogen molecule formation: The atomic number of hydrogen is $1,$ its atom contains 1 electron in K shell. It requires one more electron to complete the $K$ shell and attain the configuration of helium $(He). $ To meet this requirement two hydrogen atoms share their electrons with each other to form $H_2$ molecule. One covalent bond, i.e. a single bond is formed between two hydrogen atoms by sharing of two electrons.
$2.$ Formation of oxygen molecule:
$(1)$ The atomic number of oxygen is $8.$ The electronic configuration of oxygen is $(2, 6)$. Oxygen has $6$ electrons in the outermost shell.
$(2)$ It requires $2$ electrons to complete the L shell and attain the configuration of neon $(Ne).$
$(3)$ Each oxygen atom shares its valence electron with the valence electron of another oxygen atom to give two shared pairs of electrons which results in the formation of oxygen molecule.
$(4)$ Thus, two electron pairs are shared between two oxygen atoms, forming double covalent bond $(=).$
Example:
$1.$ Hydrogen molecule formation: The atomic number of hydrogen is $1,$ its atom contains 1 electron in K shell. It requires one more electron to complete the $K$ shell and attain the configuration of helium $(He). $ To meet this requirement two hydrogen atoms share their electrons with each other to form $H_2$ molecule. One covalent bond, i.e. a single bond is formed between two hydrogen atoms by sharing of two electrons.
$2.$ Formation of oxygen molecule:
$(1)$ The atomic number of oxygen is $8.$ The electronic configuration of oxygen is $(2, 6)$. Oxygen has $6$ electrons in the outermost shell.
$(2)$ It requires $2$ electrons to complete the L shell and attain the configuration of neon $(Ne).$
$(3)$ Each oxygen atom shares its valence electron with the valence electron of another oxygen atom to give two shared pairs of electrons which results in the formation of oxygen molecule.
$(4)$ Thus, two electron pairs are shared between two oxygen atoms, forming double covalent bond $(=).$
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