Topic 4 - Chemical bonding and structure - 4.5 Metallic bonding

Nature of science: Use theories to explain natural phenomena-the properties of metals are different from covalent and ionic substances and this is due to the formation of non-directional bonds with a "sea" of delocalized electrons. (2.2)

Understandings

A metallic bond is the electrostatic attraction between a lattice of positive ions and delocalized electrons.

The strength of a metallic bond depends on the charge of the ions and the radius of the metal ion.

Alloys usually contain more than one metal and have enhanced properties.

Applications and skills

Explanation of electrical conductivity and malleability in metals.

Explanation of trends in melting points of metals.

Explanation of the properties of alloys in terms of non-directional bonding.

Guidance

Trends should be limited to s- and p-block elements.

Examples of various alloys should be covered.