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properties of covalent bond

Covalent Bonds vs Ionic Bonds

There are two types of atomic bonds - ionic bonds and covalent bonds. They differ in their structure and properties. Covalent bonds consist of pairs of electrons shared by two atoms, and bind the atoms in a fixed orientation. Relatively high energies are required to break them (50€…-€…200 kcal/mol). Whether two atoms can form a covalent bond depends upon their electronegativity i.e. the power of an atom in a molecule to attract electrons to itself. If two atoms differ considerably in their electronegativity€…-€…as sodium and chloride do - then one of the atoms will lose its electron to the other atom. This results in a positively charged ion (cation) and negatively charged ion (anion). The bond between these two ions is called an ionic bond.

 

Features

Covalent Bonds

Ionic Bonds

State at room temperature:

Liquid or gaseous

Solid

Polarity:

Low

High

Formation:

A covalent bond is formed between two non-metals that have similar electronegativities. Neither atom is "strong" enough to attract electrons from the other. For stabilization, they share their electrons from outer molecular orbit with others

An ionic bond is formed between a metal and a non-metal. Non-metals(-ve ion) are "stronger" than the metal(+ve ion) and can get electrons very easily from the metal. These two opposite ions attract each other and form the ionic bond.

Shape:

Definite shape

No definite shape

Melting point:

low

High

Boiling point:

Low

High

Occurs between:

Two non-metals

One metal and one non-metal

Examples:

Methane (CH4), Hydro Chloric acid (HCl)

Sodium chloride (NaCl), Sulphuric Acid (H2SO4 )


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