Revision Tool Metal and Non-Metals

 3. Metal and Non-Metals  

 Physical Properties of Metals  

Following are the physical properties of metals:

Metals are hard

They are good conductors of electricity

They can be easily drawn into wires (ductile)

They can be hammered into thin sheets (malleable)

They are sonorous in nature

They are lustrous

Physical Properties of Non-Metals  

Following are the physical properties of non-metals:

Non-metals are brittle

They are bad conductors of electricity

They cannot be easily drawn into wires or beaten into sheets

They are not sonorous in nature

They are not lustrous

Metals Reaction with Air 

 

Metals reaction with Water 

 

Metals Reaction with Acid 

 

Metals reaction with Other Metal Salts  

Metals high in the reactivity series displace the lower metals when they react with a salt of the less reactive metal salt. Such a reaction is called a displacement reaction.

Examples:

Iron reacts with copper sulphate to form iron sulphate, which is pale green in colour. Since iron is higher in the reactivity series, it displaces copper from its compound.

Similarly, copper reacts with silver nitrate sulphate to form copper nitrate which is an aqueous solution. Since copper is at a higher order in the reactivity series, it displaces silver from its compound. The silver in the solution is precipitated out as metallic silver.

Reactivity Series 

 The list of metals arranged in order of their decreasing reactivity is known as the reactivity series.

Formation of Ionic Compounds  

  

When metals react with non-metals, electrons are transferred from the metal atoms to the non-metal atoms, forming ions. The resulting compound is called an ionic compound.

Metal atoms lose the electron, or electrons, in their highest energy level and become positively charged ions whereas non-metal atoms gain an electron, or electrons, to become negatively charged ions.

 Properties of Ionic Compounds  

The properties of ionic compounds are given below:

Ionic compounds are hard crystalline solids in nature.

Ionic compounds have high melting and boiling points, since a huge amount of energy is required to break the strong inter-ionic attraction.

Ionic compounds are generally soluble in water and insoluble in solvents such as kerosene, petrol etc.

Ionic compounds are good conductors of electricity.

Extraction of Metals  

Metals are extracted from the minerals or ores that are basically elements or compounds found naturally in the earth’s crust. All the metals are extracted from their respective ores using methods depending upon their position in the reactivity series.

Extraction of Metals of Low Reactivity

  Extraction of Metals of Low Reactivity  

The metals at the bottom of the activity series are least reactive. They are often found in free state. In order to extract these metals from their oxides, they are heated alone.

For example, the ore of mercury called cinnabar (HgS), is first heated in air and converted into mercury oxide. The oxide is then reduced to mercury by further heating.

Extraction of Metals of Medium Reactivity 

 These are moderately reactive metals which are present as Sulphides and Carbonates.

Carbonate or sulphide ores of metals are first converted into respective oxides and then oxides are reduced to respective metals.

Extraction of Metals of High Reactivity

  Extraction of Metals of High Reactivity  

Metals lying above carbon in the reactivity series cannot be extracted with carbon or carbon monoxide. This is because metals have more affinity for oxygen than carbon. These metals are obtained by the electrolysis of their molten chlorides.

Refining of Metals

  Refining of Metals  

Electrolytic refining is the process of separating the impurities from a metal using electrolysis. In this method, the impure metal is taken as an anode and a thin strip of pure metal is taken as a cathode. The salt of the metal is used as the electrolyte.

When current is passed through the electrolyte, metal atoms dissolve from the impure anode to form metal ions. These migrate towards the cathode, where they are deposited back as pure metal atoms. The impurities left behind at the anode settle down and form a sludge beneath it known as anode mud.

Corrosion

  Corrosion  

It is the phenomenon by which the surface of some metals gets corroded upon exposure to moist air.

Corrosion requires three conditions: moisture, a metallic surface and an electron acceptor. If you remove any of these three criteria, corrosion is inhibited.

Prevention of Corrosion  

Corrosion can be prevented using the following methods:

Applying a coating of oil, grease or paint

Galvanizing, which means applying a thin coating of zinc, over iron or steel

Electroplating, in which the metal to be protected is coated by a thin layer of another metal which has a non-rusting property

Applying a thin layer of tin

Anodizing, in which the coating of aluminium oxide which is a good electrical insulator is done on the metal to be protected

  

SimulationCorrosion can be prevented using the following methods:

Applying a coating of oil, grease or paint

Galvanizing, which means applying a thin coating of zinc, over iron or steel

Electroplating, in which the metal to be protected is coated by a thin layer of another metal which has a non-rusting property

Applying a thin layer of tin

Anodizing, in which the coating of aluminium oxide which is a good electrical insulator is done on the metal to be protected