Question { Cipla, 4254 }

how to do heavy metal test for colour sample?

Answer

charcol added with sample after decolourised then do the as
usual procedure

Question { 5778 }

why helium does not react with other elements?

Answer

helium contain completely filled orbitals so it can't react with other elementsis

chemically unreactive under all normal conditions due to its valence of zero

Question { 12051 }

define polar and non polar solvent

Answer

First of all we need to know what polar molecules are.Some elements have a greater tendency to attract electrons than the other ie they're more electronegative. So when in covalent moelcule a pair of less electronegative and a more electronegative element is present, the electrons shift from their mean position to slightly towards more electronegative. Thus the elements acquire slight charge. This is known as polar bond. The molecule so formed is known as polar molecule. e.g. In HCl, Cl is more electronegative and attracts electron towards itself, Cl acquires slight negative charge and H acquires slight positive charge. Similarly in water, Oxygen acquires negative charge and hydrogen positive
So now we can define the required as Polar solvent are those solvents which are constituted of polar molecules. e.g. Water, HCl
Non polar solvents are those solvents which are made up of non polar molecules. e.g. Carbon Disulphide, Carbon tetrachloride

Question { 3573 }

Which halogen element is used in halogen light?

Answer

iodine or bromine