The methods that are used for removing temporary hardness of water are by boiling and by Clark’s process. Adding washing soda, caustic soda and sodium phosphates are for permanent hardness removal.

At 773 Kelvin in presence of ferric oxide and chromium oxide, water gas (carbon monoxide and hydrogen) along with steam is transformed into carbon dioxide and hydrogen. This is also known as bosch process.

Electron rich hydrides are hydrides which have a greater number of electrons than required to form normal covalent bonds. Examples are hydrides of group 15, 16 and 17, excess electrons in se hydrides, are present as lone pairs of electrons.

We all know that elements in periodic table are arranged according to ir atomic numbers and atomic numbers are nothing but number of protons in that element. So hydrogen takes first place.

Yes, heavy water is called a moderator because it is used in nuclear reactors to slow down speed of neutrons. Hence above statement that ? heavy water is called as a moderator ?is considered to be true.

The order of reactivity of halogens with hydrogen is that Fluorine’s reactivity is greater than that of chlorine and chlorine?s reactivity is greater than that of bromine and bromine?s reactivity is greater than that of Iodine.

The boiling points of tritium are greater than that of deuterium and that is greater than that of hydrogen. The boiling points in kelvin of hydrogen, deuterium, and tritium are respectively 20.39, 23.67 and 25.

Heavy water is given by its chemical formula as D₂O, it was discovered by Urey in year 1932 and it can be prepared by exhaustive electrolysis of ordinary water using Nickel electrodes. It is generally colorless, odorless and tasteless liquid.

Ice floats on water, this is because of density of ice i.e. mass per unit volume (density of ice is 0.9167 g/cm³ and density of water is 1g/cm³) is lesser than that of water. This is reason, ice floats over water.

The density of tritium is greater than that of deuterium and density of deuterium is greater than that of protium. The density of protium is 0.09, density of deuterium 0.18 and density of tritium is 0.27.