Chemical Bonding Overview
Ionic bonding happens when metals meet non-metals, and it's basically a case of "opposites attract." Metals lose electrons to become positive ions, whilst non-metals gain those electrons to become negative ions. This electron transfer creates strong electrostatic attractions between the oppositely charged ions.
These ions arrange themselves in a giant ionic lattice - think of it like a 3D chess board with alternating positive and negative pieces. This structure gives ionic compounds high melting and boiling points because you need loads of energy to break those strong attractions. However, ionic compounds can't conduct electricity when solid because the ions are fixed in place.
Covalent bonding is the non-metals-only club where atoms share electrons instead of transferring them. You can spot these using dot and cross diagrams where shared pairs of electrons form the bonds. Simple covalent compounds (like water or methane) have relatively few atoms and weak forces between molecules, making them gases or liquids at room temperature.
Key Tip: Remember that ionic = transfer electrons, covalent = share electrons, metallic = sea of electrons!
Metallic bonding creates a "sea of delocalised electrons" around positive metal ions arranged in a regular lattice. These free-moving electrons are why metals conduct electricity and can be hammered into shape. Alloys (mixtures of metals) are harder than pure metals because different-sized ions prevent layers from sliding easily.
