IB Chemistry - Bonding

IB Chemistry home > Syllabus 2025 > Structure and bonding > Covalent bonding

"Co" means sharing, "valent" refers to the electrons in the outer, or valence, shell. Hence, the term covalent bonding means to share electron pairs between two outer shells of atoms in order to bond the atoms together, making a more complex particle.

There are two ways that this can occur, either each atom provides one electron for the pair, or both of the electrons are provided (donated) by one of the atoms. In the following chapter we examine the process and the consequences of both variations of covalent bonding.

Structure 1.1.1 - Elements are the primary constituents of matter, which cannot be chemically broken down into simpler substances.

  • Compounds consist of atoms of different elements chemically bonded together in a fixed ratio.
  • Mixtures contain more than one element or compound in no fixed ratio, which are not chemically bonded and so can be separated by physical methods.
  • Distinguish between the properties of elements, compounds and mixtures.


Tools and links

  • Tool 1 - What factors are considered in choosing a method to separate the components of a mixture?
  • Tool 1 - How can the products of a reaction be purified?
  • Structure 2.2 - How do intermolecular forces influence the type of mixture that forms between two substances?
  • Structure 2.3 - Why are alloys generally considered to be mixtures, even though they often contain metallic bonding?

In Section 2.1