Electrons are super important when it comes to making three main types of chemical bonds: ionic, covalent, and metallic. How these electrons are arranged and how they interact helps to create these bonds and affects the safety and qualities of different substances.

1. Ionic Bonds:

   • Ionic bonds happen when electrons are moved from one atom to another.
   • These bonds usually form between metals, which lose electrons, and non-metals, which gain electrons.
   • For example, sodium (Na) gives one electron to chlorine (Cl). This makes Na+ and Cl- ions.
   • When one mole of an ionic solid forms from gases, a lot of energy can be released, sometimes more than -800 kJ/mol.

2. Covalent Bonds:

   • Covalent bonds are created when two atoms share electrons.
   • These bonds often happen between non-metal atoms. A classic example is water (H₂O), where oxygen shares electrons with hydrogen.
   • Covalent bonds can be single (1 pair of shared electrons), double (2 pairs), or triple (3 pairs). The bond gets stronger the more electron pairs they share.
   • For a carbon-hydrogen (C–H) bond, the bond dissociation energy is about 412 kJ/mol.

3. Metallic Bonds:

   • Metallic bonds involve a "sea of electrons," where electrons can move freely around positively charged metal ions.
   • This free movement is why metals can conduct electricity and can be shaped easily. In metals like copper, most outer-shell electrons help with the bonding, which makes them good at conducting electricity.

In short, the way electrons behave is a big part of how different types of chemical bonds are made between elements.