What will be the mass of one atom of $^{12}C$ in grams?

Isotope	Relative abundance $(\%)$	Atomic mass $(u)$
$^{12}C$	$98.8$	$12$
$^{13}C$	$1.18$	$13.1$
$^{14}C$	$0.02$	$14.1$

From the above data,what is the average molecular mass of $CH_4$ containing all isotopes of carbon,assuming hydrogen is only $^{1}_{1}H$? (Given that atomic mass of hydrogen $= 1.008 \ u$)

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:

$71 \ g$ of chlorine combines with a metal to form $111 \ g$ of its chloride. The chloride is isomorphous with $MgCl_2 \cdot 6H_2O$. The atomic weight of the metal is:

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

What is the mass of one molecule of the compound $C_{60}H_{122}$ in grams?