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As we have learnt, the elements in the periodic table are classified as metals and non-metals based on their physical and chemical properties. The periodic table has approximately \(95\) metals and \(17\) non-metals.
Metal is a solid substance that is hard and shiny.
The element that does not shine, neither too hard nor soft, is called a non-metal. Hence all gases are non-metals.
The elements that exhibit the properties between metals and non-metals are called metalloids or semimetals.
Some examples for metals, semimetals and non-metals are as follows:
Elements | Examples |
Metals | Gold, silver, copper, iron, aluminium, lead, platinum, zinc, etc. |
Non-metals | Hydrogen, carbon, nitrogen, phosphorus, oxygen, sulphur, selenium, all halogens and noble gases. |
Metalloid or semimetal | Boron, silicon, germanium, arsenic, antimony, tellurium and polonium. |
Metals are often extremely strong, long-lasting, and resistant to regular wear and tear. They have been used for a variety of purposes since ancient times. Some uses of metals are as follows:
- They are used in building construction, electronics industry, pharmaceutical industry, machinery, refractory and manufacturing automobiles.
- They are also used in the aviation industry and manufacturing household items like utensils.
- Metals are used in making jewellery and other decorative items like statues etc.
Types of metals:
- Noble metals
- Alkaline metals
- Alkaline earth metals
- Transition metals
Noble metals: They are unreactive. They show outstanding resistance to chemical attacks even at high temperatures. Example for noble metals: Silver, platinum, gold and palladium.
Alkali metals: They are very reactive. They are also soft and have low melting points. Example for alkali metals: Potassium and sodium.
Alkaline earth metals: They are less reactive, have higher melting points and are harder than alkali metals. Example for alkaline earth metals: Calcium, magnesium and barium.
Transition metals: They are hard, shiny, strong, and easy to shape. Example for transition metals: Iron, chromium, nickel, and copper.
Uses of metals in daily life:
- Iron is used to make bridges, engine parts, iron-sheets and girders.
- Aluminium is used in electrical wires, cables, aerospace industries and aluminium vessels for cooking purposes.
- Copper is used to making electrical wires, coins and statue.
- Silver and gold are used to make jewels for decorative purposes and photography.
- Mercury is used in thermometers and barometers.
- Lead is used in automobile batteries and X-ray machines.
Uses of non-metals in daily life:
- Diamond is used for making jewels, cutting and grinding equipment. Graphite is used for making pencil lead.
- Sulphur is used for the manufacturing of gun powder and the vulcanization of rubber.
- Phosphorous is used for making matches, rat poison, etc.
- Nitrogen is commonly used in the manufacturing of ammonia.
- Chlorine is used in sterilizing water and used as a bleaching agent.
- Hydrogen is used as rocket fuel.
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