Question
Define atomic mass unit.
✓
Answer
Atomic Mass Unit : The mass of nuclear particle proton, neutron is so low that when expressed in kilogram units, they are of the order $10^{-27} kg$. It is not very convenient to use such small quantities. Therefore the masses of nuclei are expressed in a smaller unit. It is called atomic mass unit (a.m.u.). Considering the mass of ${ }_6 C ^{12}$ as standard, its 12 th part is equal to 1 a.m.u.
$\begin{aligned}
\text { That is, } 1 \text { a.m.u. } & =\frac{\text { Mass of } C^{12} \text { atom }}{12} \\
& =1.660565 \times 10^{-27} kg
\end{aligned}$
$\begin{aligned}
\text { That is, } 1 \text { a.m.u. } & =\frac{\text { Mass of } C^{12} \text { atom }}{12} \\
& =1.660565 \times 10^{-27} kg
\end{aligned}$
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