Which of the following is not an isotope of hydrogen?

The gases used in different types of welding would include

The hardest substance available on earth is

Permanent hardness of water may be removed by the addition of

Actinides are the elements with atomic numbers from

Which of the following metals remain in liquid for under normal conditions?

Which of the following is in liquid form at room temperature?

Galvanised iron sheets have a coating of

In fireworks, the green flame is produced because of

Chemical formula for water is

The main constituents of pearls are

The property of a substance to absorb moisture from the air on exposure is called

Production of chlorofluorocarbons (CFC) gas which is proposed to be banned in India, is used in which of the following domestic products?

The chemical (ethyl mercaptan) added to the otherwise odourless LPG cooking gas for imparting a detectable smell to the gas is a compound of

The variety of coal in which the deposit contains recognisable traces of the original plant material is

Soda water contains

The two elements that are frequently used for making transistors are

Potassium Permanganate is used for purifying drinking water, because

Sodium metal is kept under

Among the various allotropes of carbon,

Permanent hardness of water can be removed by adding

The gas usually filled in the electric bulb is

Amalgams are

In which of the following activities silicon carbide is used?

Balloons are filled with

Which of the following does not contain a coinage metal?

The element common to all acids is

Tetraethyl lead is used as

The most important ore of aluminium is

The filament of an electric bulb is made of