The unit of atomic mass,$amu$ is replaced by $u$,here $u$ stands for

The chemical formula for calcium pyrophosphate is $Ca_2P_2O_7$. The formula for ferric pyrophosphate will be

The relative abundance of two isotopes of atomic weight $85$ and $87$ is $75\%$ and $25\%$ respectively. The average atomic weight of the element is:

The mass of one molecule of oxygen is equal to $..... \ kg$.

If we consider that $1/6$ of the mass of a carbon atom,in place of $1/12$,is taken to be the relative atomic mass unit,the mass of one mole of a substance will

Statement $1$: The equivalent mass of $Cu$ in $CuO$ is $63.6$ and in $Cu_2O$ is $31.8$. Statement $2$: Equivalent mass = $\frac{\text{Molecular mass}}{\text{Valency}}$