Which of the following gas present in the

Which type of wave does not require a medium for propagation?

Law of conservation of mass is not correct for

_____ is the movement of chemicals in the upper layers of soil into lower layers or into groundwater by being dissolved in water.

The conversion of hard water into soft water by boiling or adding calcium hydroxide is called:

Water is a good solvent of ionic salts because -

Which of the following scientists invented steam engine?

Bleaching powder is represented as ______.

What is the nature of the pH of milk?

Who proposed the 'Law of Octaves' in the periodic classification of elements?

Ethane gas has a slightly _____ taste.