Covalent Bonds | Chemistry for GCSE/IGCSE - Year 11 PDF Download

The Formation of Covalent Bonds

Covalent Compounds

• Covalent compounds are formed when pairs of electrons are shared between atoms
• Only non-metal elements participate in covalent bonding
• As in ionic bonding, each atom gains a full outer shell of electrons, giving them a noble gas electronic configuration
• When two or more atoms are covalently bonded together, we describe them as 'molecules'
• Dot-and-cross diagrams can be used to show the electron configurations in simple molecules
• Electrons from one atom are represented by a dot, and the electrons of the other atom are represented by a cross
• The electron shells of each atom in the molecule overlap, and the shared electrons are shown in the area of overlap
• The dot-and-cross diagram of the molecule clearly indicates the origin of each electron

Edurev Tip: When creating dot-and-cross diagrams for covalent compounds, ensure that each atom's electron shell is complete. Remember that the first shell can accommodate a maximum of two electrons.

Single Covalent Bonds

Many simple molecules exist in which two adjacent atoms share one pair of electrons, forming a single covalent bond.

Common Examples of Simple Molecules