Bonding - OCR GatewayMetallic structure and bonding
Ionic bonds, covalent bonds and metallic bonds are examples of chemical bonds. The structure and bonding in a substance are modeled in different ways, including dot and cross diagrams.
In metals, the electronSubatomic particle, with a negative charge and a negligible mass relative to protons and neutrons. leave the outer shells of metal atomThe smallest part of an element that can exist., forming positive metal ionElectrically charged particle, formed when an atom or molecule gains or loses electrons. and a ‘sea’ of delocalisedElectrons that are not associated with a particular atom, eg in a metal, outer electrons can be free to move through the solid. electrons. The structure of a solid metal consists of closely packed metal ions, arranged in a regular way to form a metallic latticeA regular grid-like arrangement of atoms in a material. structure.
Figure caption,
A model for the structure of metals
Chemical formulae
Metallic lattices do not contain fixed numbers of atoms. This means that the chemical formula used for a metal is simply the symbol for the element. For example, the formula for iron is Fe, even though a piece of iron contains very many iron atoms.