Naturally occurring boron has $20\%$ $_5B^{10}$ and $80\%$ $_5B^{11}$. The average atomic weight of boron is

If the mass of an electron is halved,the mass of a proton is doubled,and the mass of a neutron is $3/4$ of its original mass,then what will be the new atomic mass of an $O^{16}$ atom?

Vapour density of a gas is $22$. What is its molecular mass?

An appropriate method for molecular weight determination of chloroform $(CHCl_3)$ is:

An element $X$ reacts with oxygen to form a compound $X_2O_3$. If the atomic mass of $X$ is $91.5$,the equivalent mass of $X$ is:

The oxide of a metal contains $40 \%$ of oxygen. The valency of the metal is $2$. What is the atomic weight of the metal?