Copper coins and silver coins get a coating because of the phenomenon of corrosion. Copper coins react with carbon dioxide and moisture in the atmosphere to form copper carbonate. Silver coins react with sulphur in the atmosphere to form a coating of silver sulphide.
Copper coins and silver coins get a coating because of the phenomenon of corrosion.
Copper coins react with carbon dioxide and moisture in the atmosphere to form copper
carbonate.
Silver coins react with sulphur in the atmosphere to form a coating of silver sulphide.
Rahul has been collecting copper coins and silver coins. One day he observed a green coating on copper coins and a black coating on silver coins. State the chemical phenomenon responsible for these coatings and also write chemical names of each coating.
Copper coins and silver coins get a coating because of the phenomenon of corrosion. Copper coins react with carbon dioxide and moisture in the atmosphere to form copper carbonate. Silver coins react with sulphur in the atmosphere to form a coating of silver sulphide.
Copper coins and silver coins get a coating because of the phenomenon of corrosion.
See lessCopper coins react with carbon dioxide and moisture in the atmosphere to form copper
carbonate.
Silver coins react with sulphur in the atmosphere to form a coating of silver sulphide.
Write a balanced chemical equation to show the chemical change that occur when magnesium ribbon is burnt in air. Name the product formed and mention the characteristics of the flame produced.
2Mg (s) + O ₂ (g) ⟶ 2MgO (s) A dazzling white flame is obtained when magnedium ribbon is burnt in air
2Mg (s) + O ₂ (g) ⟶ 2MgO (s)
See lessA dazzling white flame is obtained when magnedium ribbon is burnt in air
Name any one material used to make a solar cell and also mention the range of voltage produced by a typical cell.
Silicon is most common material used to make a solar cell. A typical cell produces a voltage ranging from 0.5 to 1.0 volt.
Silicon is most common material used to make a solar cell. A typical cell produces a
See lessvoltage ranging from 0.5 to 1.0 volt.
List any two factors on which resistance of a conductor depends.
The resistance of a conductor depends on its length, its area of cross-section and the nature of its material.
The resistance of a conductor depends on its length, its area of cross-section and the nature of its material.
See lessState one challenge to free and fair elections in India.
In some cases, the candidates with criminal connection have been able to secure a 'ticket' from major parties.
In some cases, the candidates with criminal connection have been able to secure a ‘ticket’ from major parties.
See less