The formation of covalent bonds
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
Covalently bonded substances may consist of small molecules or giant molecules
When two or more atoms are covalently bonded together, we describe them as ‘molecules’
Dot-and-cross diagrams can be used to show the electronic 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 shows clearly which atom each electron originated from
Single Covalent Bonds
Many simple molecules exist in which two adjacent atoms share one pair of electrons, also known as a single covalent bond (or single bond)
Common Examples of Simple Molecules
