Chemical Bonding and Structure
Ever wondered why diamond is so hard but graphite is soft? It's all about how atoms bond together! There are three main types of chemical bonding: ionic, covalent, and metallic.
Ionic bonding happens when metals meet non-metals. The metal loses electrons to become a positive ion, whilst the non-metal gains electrons to become negative. These oppositely charged ions attract each other strongly, creating giant ionic structures like salt (NaCl). These compounds have high melting points because you need loads of energy to break those strong electrostatic forces.
Covalent bonding occurs between non-metals that share electrons. In small molecules like water (H₂O), the bonds between atoms are strong, but the forces between molecules are weak - that's why water boils easily. Polymers like polyethene are long chains of repeating units joined by covalent bonds.
Metallic bonding creates the unique properties of metals. Positive metal ions are surrounded by a "sea" of delocalised electrons that can move freely. This explains why metals conduct electricity and can be hammered into shape without breaking.
Key insight: The type of bonding determines a material's properties - from whether it conducts electricity to how easily it melts!
