Metals, Non-metals, and Carbon Compounds
This domain tests the physical and chemical differences between metals and non-metals, the reactivity series, alloys and corrosion, and the basic chemistry of carbon compounds.
Core rules
- Metals are generally lustrous, malleable, ductile, sonorous, and good conductors of heat and electricity. Non-metals are usually brittle, dull, and poor conductors, though graphite is a non-metal that conducts electricity.
- The reactivity series ranks metals by tendency to lose electrons. A more reactive metal displaces a less reactive metal from its salt solution.
- Alloys are mixtures of a metal with other elements, made to improve properties such as hardness or corrosion resistance. Rusting of iron needs both oxygen and moisture.
- Carbon exists as allotropes including diamond, graphite, and fullerene. Carbon compounds include hydrocarbons; ethanol and ethanoic acid are common functional-group examples. Soaps are salts of fatty acids and form micelles in water.
Worked example
A piece of zinc is placed in blue copper sulphate solution. Zinc is above copper in the reactivity series, so zinc displaces copper: Zn + CuSO4 → ZnSO4 + Cu. The blue colour fades as Cu2+ ions are removed, and a reddish-brown copper deposit forms on the zinc. This is a displacement reaction, not a double displacement.
Traps that cost marks
Do not classify graphite as a metal because it conducts. Do not call an alloy a compound; its components are not chemically combined in a fixed ratio. Do not say rusting needs only air; moisture is also necessary. In carbon chemistry, distinguish ethanol from ethanoic acid by smell and by reaction with sodium carbonate.
Key points
- Metals conduct and are malleable; non-metals are generally brittle insulators.
- Reactivity series predicts displacement reactions.
- Alloys are mixtures designed for better properties.
- Carbon allotropes differ in structure and properties.