Formation of covalent bond in chlorine molecule

Formation of  hydrogen chloride molecule, HCl ( covalent compound)

The formation of covalent bonds in hydrogen chloride molecule is explained as follows:

§  Each hydrogen atom has an electron arrangement of 1.

§  The outermost shell needs one electron in order to achieve a stable duplet electron arrangement.

§  Clorine atom has an electron arrangement of 2.8.7.

§  The outermost shell needs one electron in order to achieve a stable octet electron arrangement.

§  Clorine atom contributes one valence electron while hydrogen atom contributes one valence electron for sharing.

§  A single covalent bond is formed.

Remarks:

§  The electrons must be drawn in the overlap of two shells.

§  Students may use Lewis structure in drawing the formation of covalent compound. ( Lewis structure only show the valence electrons)

Formation of sodium chloride, NaCl ( ionic compound)

The formation of ionic bonds in sodium chloride, NaCl is explained as follows:

•    The electron arrangement of a sodium atom is 2.8.1.
•     Sodium atom releases one valence electron to form sodium ion, Na⁺

                             Na → Na⁺ + e

• The electron arrangement of sodium ion is 2.8.
• Sodium ion achieves a stable octet electron arrangement.
• The electron arrangement of a chlorine atom is 2.8.7.
• Chlorine atom receives one electron to form chloride ion, Cl^-

                             Cl + e → Cl^-

• The electron arrangement of chloride ion is 2.8.
•  Chloride ion achieves a stable octet electron arrangement.
•  Strong electrostatic force pulls the sodium ion and chloride ion together.
• An ionic bond is formed.
• Sodium chloride is an ionic compound.

Remark:
Students always confuse following terms.
chlorine is atom
choride is ion


When answer this question, please draw the diagram of formation of ionic bond in sodium chloride because some time the diagram will contribute marks for you.