Answer:
<u><em>The answer is</em></u>: <u>The twelfth part (1/12) of the mass of an atom, neutral and unbound, of carbon-12.</u>
<u></u>
Explanation:
<em>The unit of unified atomic mass - symbol "u" -1 or dalton - symbol "Da" - is a standard unit of mass defined as</em> the twelfth part (1/12) of the mass of an atom, neutral and unbound , of carbon-12,<em> in its fundamental electrical and nuclear state, and is equivalent to 1,660 538 921 (73) × 10-27 kg (value recommended by CODATA).
</em>
<u><em>The answer is</em></u>: <u>The twelfth part (1/12) of the mass of an atom, neutral and unbound, of carbon-12.</u>