Class 8 Science

Metals Non-metals

Metals: Metals are lustrous, sonorous, ductile, and are good conductor of heat and electricity.

Non-metals: Non-metals are no-lustrous, non-sonorous, non-ductile, and are bad conductor of heat and electricity.

Table of Contents

Malleability: Metal can be beaten into thin sheets. This property of metals is called malleability.

Ductility: Metals can be pulled to make thin wire. This property of metals is called ductility.

Sonority: Metals produce a typical ringing sound when hit by something. This property is called sonority or sonorousity.

Physical Properties

Conductivitygood conductors of heat and electricityBad conductor
Ductilityductilenon ductile
Sonoroussonorousnon sonorous
Lustroushave metallic shineare usually dull
Physical StateMost are solid at room temperatureavailable in all the three states of matter

Chemical Properties of Metals and Non-metals

Reaction with Oxygen

Metals react with oxygen to form metallic oxides. Metallic oxides are basic in nature.

Example: Iron reacts with oxygen and moisture to form iron oxide. Iron oxide is brown in colour and is commonly known as rust.

Fe + O2 + H2O → Fe2O3

Example: Magnesium reacts with oxygen when it is burnt and forms magnesium oxide.

Mg + O2 → 2MgO

Example: When copper is exposed to moist air for a long time, it acquires a greenish coating. The green coat is because of formation of copper hydroxide and copper carbonate.

2Cu + H2O + CO2 + O2 → Cu(OH)2 + CuCO3

Non-metals also react with oxygen to make oxides. Oxides of non-metals are acidic in nature.

Example: Sulphur reacts with oxygen when it is burnt. It forms sulphur dioxide.

S + O2 → SO2

When sulphur dioxide is dissolved in water, it forms sulphurous acid.

SO2 + H2O → H2SO3

Reaction with water

Some metals react vigorously with water, while some others do not react at all with water.

Example: Sodium is a highly reactive metal and reacts vigorously with water. This is a highly exothermic reaction. During this reaction; sodium catches fire because of too much heat being evolved. Due to this, sodium is stored in kerosene to prevent accidental fire.

Usually, non-metals do not react with water, but some non-metals react vigorously with air. Such non-metals are stored in water to prevent their reaction with air. For example, phosphorus is stored in water to prevent its reaction with air.