Question

Which non-metal catches fire, if exposed to air?Explain ​

Answer 1

Answer:

Phosphorus

Explanation:

It is very reactive non metal. It catches fire, if exposed to air. To prevent the contract of phosphorus with atmospheric oxygen, it is stored in water..

Answer 2

Phosphorus is the non-metal which catches fire, if exposed to air.

Metals

Iron, copper, tin, gold etc. are metals. In general, metals are hard and shiny in appearance.

Non- Metals

Sulphur, phosphorus, hydrogen, oxygen, nitrogen, carbon etc. are non-metals. In general, they are not so hard with dull appearance.

1) Physical properties of metals and non-metals:- Mercury is the only metal known to occur in liquid state in nature, at room temperature.

Non-metals are generally solid or gases. Bromine is the only non-metal which exists in liquid state.

2) Malleability and brittleness:- The property which allows metals to be hammered into thin sheets or fouls is called malleability.

Examples:-

• Gold
• Silver
• Aluminium
• Copper

However zinc is also a metal but it breaks into pieces on hammering that's why it is brittle in nature.

Brittleness:-The property due to which non-metals break up into pieces on hammering is called brittleness.

Examples:-

• Sulphur
• Coal

3) Ductility:- The property which allows the metals to be drawn into thin wires is called ductility.

Examples:-

• Gold
• Silver
• Iron
• Aluminium
• Copper
• Magnesium

Non-metals are not ductile:- When stretched, non-metals like phosphorus and sulphur break into pieces do not form wires.

4) Lustre:- Most of the metals are lustrous with shiny surface.

Examples:-

• Gold
• Silver
• Platinum

Non-metals do not have shiny appearance. However some of them are little lustrous.

Examples:-

• Graphite
• Iodine

5) Conductivity of heat:- Metals are good conductor of heat. However Bismuth is the only metal i.e. bad conductor of heat.

Non-metals are bad conductors of heat. However Diamond is the only non-metal i.e. good conductor of heat.

6) Hardness:- Metals are generally hard.

Example:- Iron

However sodium and potassium are metals that are not hard and be easily cut through a knife.

Non-metals are not hard and strong.

Example:- Diamond

7) Tensile strength:- The property which allows a substance to bear a lot of strain without breaking is called tensile strength like zinc. However zinc has low tensile strength.

Non- metals have low tensile strength so they break easily. However carbon fibre, has high tensile strength.

8) Density:- Metals have high densities, but sodium and potassium have low density.

Non- metals have low densities. However Diamond has high density.

9) Conductivity of electricity:- All metals are good conductor of electricity. Silver is best metal i.e. conductor of electricity.

Non-metals are poor conductors of electricity.

Examples:- Sulphur, phosphorus.

However graphite i.e. a non-metal is a good conductor of electricity.

10) Sonority:- The property of producing a ringing sound by a metal when it strikes with a hard material is called Sonority.

All metals are sonorous.

Non-metals are non sonorous as they don't make ringing sound on striking with each other.

11) Melting and boiling point:- Metals generally have high melting and boiling point. However sodium, potassium, mercury and gallium that are metals have low melting point.

Non-metals have low melting and boiling point. However Diamond has a very high melting point.