Single, Double and Triple Covalent Bonds

As explained on the previous page, two atoms can share a pair of electrons to form a covalent bond.

It is also possible for two atoms to share two pairs of electrons or three pairs of electrons.

These bonds are named according to how many pairs of electrons are shared:

When only one pair of electrons is shared, it is called a single covalent bond.

When two pairs of electrons are shared, it is called a double covalent bond.

When three pairs of electrons are shared, it is called a triple covalent bond.

It is not possible for two atoms to share more than three pairs of electrons.

The diagram below shows two chlorine atoms held together by a single covalent bond. We can tell that it is a single bond because in the region where the outer shells overlap there is only one pair of electrons (that is, two electrons).

Two chlorine atoms held together by a single covalent bond.

The diagram below shows two oxygen atoms held together by a double covalent bond. We can tell that it is a double bond because in the region where the outer shells overlap there are two pairs of electrons (that is, four electrons).

Two oxygen atoms held together by a double covalent bond.

The diagram below shows two nitrogen atoms held together by a triple covalent bond. We can tell that it is a triple bond because in the region where the outer shells overlap there are three pairs of electrons (that is, six electrons).

Two nitrogen atoms held together by a triple covalent bond.

Flashcards

Flashcards help you memorise information quickly. Copy each question onto its own flashcard and then write the answer on the other side. Testing yourself on these regularly will enable you to learn much more quickly than just reading and making notes.