Covalent & Dative Bonding
Chemistry: AQA A Level, topic 1.3.2
Covalent Bonding
Covalent bonding happens between non-metals.
Covalent bonds
- A covalent bond is one that contains a shared pair of electrons.
- Usually, each atom gives one electron to the bond.
- Molecules have covalent bonds holding the atoms together.
- Covalent bonds are strong because the shared electrons are attracted to the nucleus of both atoms.
Multiple bonding
- Atoms can also form double (e.g. O2) or triple (e.g. N2) covalent bonds.
- There are rare examples of quadruple, quintuple, and even sextuple bonds between some heavy metal compounds.
- Multiple bonds contain shared pairs of electrons just like single bonds.
- Multiple bonds are usually stronger than single bonds.
Dative Bonding
A dative bond is a special kind of covalent bond.
Dative bonds
- A dative bond is a covalent bond in which both electrons in the bond come from one atom.
- Dative bonds are sometimes called coordinate bonds.
E.g. Ammonium ion
- Ammonium ions are made of an ammonia molecule that has attached to a hydrogen ion with its lone pair.
- Both electrons for the coordinate bond come from the nitrogen atom.
Test yourself on Covalent & Dative Bonding
Which is the best description of a covalent bond?
Which of the following are properties of covalent bonds?
Typical Bond Strength
Which of these is another name for a dative bond?
Which of the following is true of dative bonds?