Mammoth Memory

Chemical bonding

Bonding is about atoms achieving full outer shells or orbits.

There are three key types of bonding:

  • ionic
  • covalent (including simple covalent structures and giant covalent structures)
  • metallic


The two main types of bonding are ionic bonding and covalent bonding.

Ionic (transfer)

Ionic bonding is the transfer of electrons.

The sodium and chloride ions attract each other.

Sodium transfers an electron to chlorine to make a positive sodium ion and a negative chloride ion.

The sodium and chloride ions attract each other like magnets and are joined by an ionic bond.

Because they are oppositely charged, the ions are attracted to each other like magnets and an ionic bond is formed.

image showing how atoms bond to create a solid


Covalent bonding (sharing)

Covalent bonding is the sharing of electrons.

image explaining hydrogen and oxygen electrons

Two hydrogen atoms are needed to complete oxygen’s outer shell and form a covalent compound (H2O).

diagram of covalent bonds

Note for higher tier Chemistry students

Some compounds contain both ionic and covalent bonds such as sodium nitrate NaNO3, sodium hydroxide NaOH and calcium carbonate CaCO3.

image showing how hydroxide attracts to sodium

Metallic bonding

Metallic bonding involves a sea of electrons.

diagram showing how metal atoms bond

A sea of electrons around positive metal ions. 

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