Question-What is metals?
Answer-Metals-The elements which are hard, shiny can be beaten into sheets, drawn into wires and are good conductor of heat and electricity are generally metals. For example: iron, copper, gold etc.
• In nature most metals occur in the combined state as minerals and they are reactive.
• Only a few unreactive metals like gold, silver, platinum are found as free metals in the earth’s crust.
• Minerals from which metals can be profitably extracted are called ores. For example: calcium occurs in limestone (calcium carbonate) or iron in the ore haematite.
Physical properties of Metals:
1. Metals are solids at room temperature, except mercury, which is liquid at room temperature.
2. They are generally hard and strong but sodium and potassium are soft solids and can be cut with a knife.
3. They are good conductor of heat and electricity. Copper is the best conductor of electricity followed by gold and aluminium.
4. Metals such as gold, silver and copper all have lustre, that is they have an ability to shine and reflect light. Therefore they are lustrous.
5. The property by virtue of which metal can be beaten into sheets is called malleability. We use aluminium foil to pack food.
6. The property by which metals can be drawn into wires is called ductility. Metals like copper, silver and aluminium can be drawn into wires.
7. Metals are sonorous. They produce sound when struck.
8. With the exceptions of sodium, potassium and mercury most of the metals have high melting and boiling point.
9. Metals have high densities.
10. Most metals have high tensile strength.
Answer-Metals-The elements which are hard, shiny can be beaten into sheets, drawn into wires and are good conductor of heat and electricity are generally metals. For example: iron, copper, gold etc.
• In nature most metals occur in the combined state as minerals and they are reactive.
• Only a few unreactive metals like gold, silver, platinum are found as free metals in the earth’s crust.
• Minerals from which metals can be profitably extracted are called ores. For example: calcium occurs in limestone (calcium carbonate) or iron in the ore haematite.
Physical properties of Metals:
1. Metals are solids at room temperature, except mercury, which is liquid at room temperature.
2. They are generally hard and strong but sodium and potassium are soft solids and can be cut with a knife.
3. They are good conductor of heat and electricity. Copper is the best conductor of electricity followed by gold and aluminium.
4. Metals such as gold, silver and copper all have lustre, that is they have an ability to shine and reflect light. Therefore they are lustrous.
5. The property by virtue of which metal can be beaten into sheets is called malleability. We use aluminium foil to pack food.
6. The property by which metals can be drawn into wires is called ductility. Metals like copper, silver and aluminium can be drawn into wires.
7. Metals are sonorous. They produce sound when struck.
8. With the exceptions of sodium, potassium and mercury most of the metals have high melting and boiling point.
9. Metals have high densities.
10. Most metals have high tensile strength.
