Which of the following are the ingredients of gun metal?

From which mineral is radium obtained?

What is laughing gas?

Actinides are the elements with atomic numbers from

The two elements that are frequently used for making transistors are

The filament of an electric bulb is made of

Diamond is an allotropic form of:

In fireworks, the green flame is produced because of

Permanent hardness of water can be removed by adding

Marsh gas is