Metals and Non-metals — The Reactivity Series, Extraction and Every Alloy Exams Ask

Metals, Non-metals and the Exceptions That Get Tested

The general rules are easy. Metals are lustrous, malleable, ductile, sonorous and good conductors of heat and electricity. Non-metals are dull, brittle and poor conductors. Metal oxides are basic; non-metal oxides are acidic (CO₂ + H₂O → H₂CO₃).

Papers almost never test the rule. They test the exception:

• ›Mercury is a metal but a liquid at room temperature. Bromine is the only liquid non-metal — the pair is designed to be confused.
• ›Gallium and caesium melt in your palm; sodium and potassium are soft enough to cut with a knife.
• ›Iodine is a non-metal but lustrous. Graphite, a form of carbon, conducts electricity. Diamond, also carbon, is the hardest natural substance.
• ›Silver is the best conductor of heat and electricity, then copper. Lead is the poorest metallic conductor.
• ›Aluminium is the most abundant metal in the earth's crust; oxygen is the most abundant element in it.

1. Which of the following is a metal that is liquid at room temperature?

2. Aqua regia, which can dissolve gold, is a mixture of concentrated HCl and concentrated HNO₃ in the ratio:

3. German silver is an alloy of:

4. Heating a carbonate ore strongly in the absence or limited supply of air is called:

5. In the thermite reaction used to weld broken railway tracks, the reducing agent is:

6. Which of the following metals does NOT liberate hydrogen gas on reaction with dilute hydrochloric acid?

7. Cinnabar is the principal ore of which metal?

8. Galvanisation protects iron from rusting by coating it with a layer of: