Chemical Bond

Key Stage 4

Meaning

A chemical bond is a force of attraction holding the atoms inside a molecule together.

About Chemical Bonds

There are three types of chemical bond you should know:

• Covalent Bonds - In which atoms share electrons with one another.
• Ionic Bonds - In which electrons are transferred from one atom to another.
• Metallic Bonds - In which some electrons move freely between atoms creating lattice of positively charged ions surrounded by a sea of delocalised electrons (free electrons).

Examples

Covalent Bonds

The two Oxygen atoms each share two of their electrons with one another.	The two Nitrogen atoms each share three of their electrons with one another.	Each Oxygen shares two of its electrons with the Carbon atom while the Carbon atom shares two electrons with each Oxygen atom.

Ionic Bonds

The Lithium atom donates an electron from its outer shell to the outer shell of the Fluorine atom.	The Magnesium atom donates two electrons from its outer shell to the outer shell of the Oxygen atom.	The Beryllium atom donates an electron from its outer shell to the outer shell of each Fluorine atom.

Metallic Bonds

The outer shells of the Magnesium atoms overlap allowing the two electrons in each outer shell to move freely between atoms.	The outer shells of the Aluminium atoms overlap allowing the three electrons in each outer shell to move freely between atoms.