Deionized water is obtained by passing hard water through

The metal salts formed during the softening of hard water using $Clark's$ method are:

Zeolite is hydrated sodium aluminium silicate. When treated with hard water,the sodium ions in zeolite are exchanged with

Some statements about heavy water are given below:
$(i)$ Heavy water is used as a moderator in nuclear reactors.
$(ii)$ Heavy water is more associated than ordinary water.
$(iii)$ Heavy water is more effective solvent than ordinary water.
Which of the above statements are correct?

Which of the following is heavy water?

The process used for the removal of hardness of water is