Boron has two stable isotopes,$^{10}B$ $(19\%)$ and $^{11}B$ $(81\%)$. What will be its atomic mass in the periodic table?

The equivalent weight of a metal is $4.0$. The vapour density of its chloride is $59.25$. Its atomic weight is

Chlorine has two naturally occurring isotopes,${}^{35}Cl$ and ${}^{37}Cl$. If the atomic mass of $Cl$ is $35.45$,the ratio of natural abundance of ${}^{35}Cl$ and ${}^{37}Cl$ is closest to (in $: 1$)

The mass of one mole of a substance in grams is called ....... .

The approximate atomic weight of an element is $26.89$. If its equivalent weight is $8.9$,the exact atomic weight of the element would be:

The ratio of the mass of '$x$' atoms of an element to the mass of '$x$' carbon atoms is $9:1$. Find the molar mass of the element if the molar mass of carbon is $12 \text{ g/mol}$. (in $\text{ g/mol}$)