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 bondsconsist 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.
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 |
What is it?: | Covalent bonding is a form of chemical bonding between two non metallic atoms which is characterized by thesharing of pairs of electrons between atoms and other covalent bonds. | Ionic bond, also known as electrovalent bond, is a type of bond formed from the electrostatic attraction between oppositely charged ions in a chemical compound. These kinds of bonds occur mainly between a metallic and a non metallic atom. |
Boiling point: | Low | High |
Examples: | Methane (CH4), Hydro Chloric acid (HCl) | Sodium chloride (NaCl), Sulphuric Acid (H2SO4 ) |
Occurs between: | Two non-metals |
No comments:
Post a Comment