Question

Distinguish between the terms electronegativity and electron affinity, covalent bond and ionic bond, and pure covalent bond and polar covalent bond. Characterize the types of bonds in terms of electronegativity difference. Energetically, why do ionic and covalent bonds form?

Short answer

Answer :

Electronegativity is the tendency of an atom to attract towards itself in a compound electron affinity the amount of energy released when an electron is added in a neutral atom.

In a covalent bond, there is mutual sharing of electrons but in an ionic bond, there is a complete transfer of an electron.

A pure covalent bond is stated as to when there is no difference in electronegativity, but when there is a difference between electronegativity.

Based on electronegativity there are three types of bond pure covalent bond, polar covalent bond, and ionic bond.

Strong electrostatic attraction between two oppositely charged ions, the ionic bond formed.

Sharing of pair of electron between two atoms result in a covalent bond,

Step-by-step solution

differentiating between the electronegativity and electron affinity

Electronegativity is a chemical property and is defined as the tendency to attract electrons towards itself by an atom,for example, fluorine is with highest electronegativeelement in the periodic table. On the other hand electron affinity of a neutral atom (in the gas phase) is a change in energy or liberated energy when an electron is added to that atom for example chlorine is with electron affinity.

differentiating between the covalent bond and ionic bond

A covalent bond is formed between non-metals. There is sharing of electrons between non-metal atoms for example ClF is a covalent compound because there is a covalent bond between Cl and F.

In an ionic bond, there is a complete transfer of an electronfrom one atom to another atom, for example, NaCl is an ionic compound because there is a complete transfer of an electron from Na to Cl.

differentiating pure covalent bond and polar covalent bond

Pure covalent bonds are whenthere is no electronegativity difference or negligible difference i.e. equal sharing of electrons between atoms for example Cl_2.

Polar covalent bonds are when there is an electronegativity difference between atoms i.e. there is no equal sharing of electrons for example HCl.

types of bond based on electronegativity difference

When there is no electronegativity differencebetween atoms of the compound then it is a pure covalent bond for example H₂.

When there is an electronegativity difference between atoms of the compound then it is a polar covalent bond for example ICl.

When there is a large electronegativity difference between atoms of the compound then it is an ionic bond for example NaCl.

explaining why ionic bond and covalent bond formation takes place

Covalent bonds form because of the sharing of electrons between atoms of the compound to complete its octet.

Ionic bond formation takes place due to electrostatic interactionbetween two oppositely charged ions formed by donating and accepting electrons.