The ratio of the viscosity (in centipoise) of $D_2O$ to that of $H_2O$ at $25^{\circ} C$ is

Oxygen was discovered by

Which of the following statements is not true?

What properties of water make it useful as a solvent? What types of compounds can it $(i)$ dissolve and $(ii)$ hydrolyse?

Given below are two statements:
Statement-$I$: Permutit process is more efficient compared to the synthetic resin method for the softening of water.
Statement-$II$: Synthetic resin method results in the formation of soluble sodium salts.
In the light of the above statements,choose the most appropriate answer from the options given below:

Which of the following statements is/are correct?