You are given a hammer, a battery, a bulb, wires and a switch.
$(a)$ How could you use them to distinguish between samples of metals and non-metals ?
$(b)$ Assess the usefulness of these tests in distinguishing between metals and non-metals.
$(a) $ With the hammer, we can beat the sample and if it can be beaten into thin sheets (that is, it is malleable), then it is a metal otherwise a non-metal. Similarly, we can use the battery, bulb, wires, and a switch to set up a circuit with the sample. If the sample conducts electricity, then it is a metal otherwise a non-metal.
$(b)$ The above tests are useful in distinguishing between metals and non-metals as these are based on the physical properties. No chemical reactions are involved in these tests.
Give reasons : Platinum, gold and silver are used to make jewellery.
What are amphoteric oxides? Give two examples of amphoteric oxides.
Why do ionic compounds have high melting points ?
Write equations for the reactions of
$(i)$ iron with steam
$(ii)$ calcium and potassium with water
Give reasons : Carbonate and sulphide ores are usually converted into oxides during the process of extraction.