C-03-Q103mediumsingle_mcqC-12 আইসোটোপের ভরের 112\frac{1}{12}121 অংশ কত?a1.66×10−241.66 \times 10^{-24}1.66×10−24 gb9.11×10−319.11 \times 10^{-31}9.11× g