Metals and alloys

2.1.5 Nanoparticles

2.2 Related calculations

Metals and alloys

  1. Metals

    1. Metals consist of giant lattices of atoms
    2. The electrons in the highest energy level of metal atoms are delocalised and so free to move through the whole structure
    3. This corresponds to a structure of positive ions with a sea of electrons between the ions holding them together by strong electrostatic forces
    4. Metals conduct heat & electricity due to the delocalised electrons in their structures, since conduction depends on the ability of electrons to move throughout the metal
    5. Metals can be bent and shaped since the layers of atoms in metals are able to slide over each other

  2. Alloys

    1. Alloys are normally made from two or more metals
    2. Alloys are harder than pure metals since the different sizes of atoms in the metal distort the layers in the structure, making it more difficult for them to slide over each other
    3. Most metals in everyday use are alloys since pure copper, gold, iron and aluminium are too soft for many uses so are mixed with small amounts of other metals to make them harder for everyday use
    4. Shape memory alloys can return to their original shape after being deformed, such as nitinol, an alloy of nickel & titanium, which can undergo deformation at one temperature, then recover its original, undeformed shape upon heating above its “transformation temperature”; it is used in dental braces