Metallic Bonding
Metallic bonding is formed between metals.
The nuclei of atoms and inner level electrons form ions lattice.
Valence electrons are delocalized (they do not belong to any atom in particular but to the whole, and flow free among the metallic ions which are arranged in a lattice or network.
PROPERTIES OF METALS
The model of the bonding in metals accounts for the properties shown by metals in general:
metals have high melting and boiling temperatures (strong attraction between lattice ions and sea of electrons)
metals have high densities (atoms are packed together)
metals are good conductors of heat and electricity. (Sea of electrons allows an electric current to flow)
metals are malleable (can be bent or hammered into different shapes) and ductile They can be pulled into wires
Malleability
Ductility
ALLOYS
- An alloy is a mixture of two or more elements, where at least one element is a metal. Many alloys are mixtures of two or more metals.
- Pure metals are soft because the layers of ions are free to slide over each other.
- In an alloy the structure is distorted, and the alloy’s ions get harder to slide over each other. (alloys are harder than pure metals)
