sie actuallu em not getting dat ...if the compound is conataining any impurity ...even if its single basic unit i.e as uh said entity consists o f impurity den d total ratio of the mass must change...must vary...den y its d d same???

Dear student,

When impurity is introduced in a crystal lattice then it results in the change in the mass ratio. If the mass of the impurity is more then mass ratio will increases and if it is less then it will results in decrease in the mass ratio.

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