The heaviest atom amongst the following is

The molecular weight of a tribasic acid is $M$. What will be its equivalent weight?

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

One gram of hydrogen is found to combine with $80 \ g$ of bromine. One gram of calcium (valency $= 2$) combines with $4 \ g$ of bromine. The equivalent weight of calcium is:

The modern atomic weight scale is based on

If the mass table of atomic weights were established with oxygen atom assigned a value of $100,$ the atomic weight of carbon would be