Question

the atomic mass of carbon - 12 is amu.

Explanation:

Step1: Recall the definition of atomic mass unit

By definition, one atomic mass unit (amu) is defined as $\frac{1}{12}$ of the mass of a Carbon - 12 atom.

Step2: Calculate the atomic mass of Carbon - 12

If we let the mass of Carbon - 12 be $m$. Since $1\ amu=\frac{m}{12}$, then $m = 12\ amu$.

Answer:

$12$