Question

The unified atomic mass unit is the standard unit that is used for indicating mass on an atomic or molecular scale. If true enter $1$ else enter $0$.

Answer 1

Hint: As we know a unified mass unit which is represented as Da or u is a unit which is used to represent atomic and molecular mass and it is widely used both in the field of chemistry and physics. We can try to represent it in terms of mass of unbound carbon $12$ atoms and from there we can express the unified atomic mass unit in terms of $gmo{l^{ - 1}}$ .

Complete step by step answer:
The unified atomic mass unit is the standard unit that is used for indicating mass on an atomic or molecular scale (atomic mass). One unified atomic mass unit is approximately the mass of one nucleon which can be either a single proton or a neutron and is equivalent to \[1{\text{ }}g/mol\]. It can be defined as one twelfth of the mass of an unbound neutral atom of \[carbon - 12\]in its nuclear and electronic ground state and has a value of \[1.66 \times 1027kg\].
The relationship between the unified atomic mass unit and the macroscopic SI base unit of mass denoted as $kg$ is given by Avogadro’s number represented as ${N_A}$ . From the definition of Avogadro’s number we can say that the mass of ${N_A}{{\text{ }}^{12}}{{\text{C}}_{}}$ atoms at rest and also in their ground state is $12g = (12 \times {10^{ - 3}})kg$
Hence it is true.

Note: We should be more careful to not get confused between the unified atomic mass unit or Dalton with the unit of mass in the atomic unit systems, which is the electron rest mass denoted as ${m_e}$ . Keep note that $1{\text{ Da}} \approx {\text{1gmo}}{{\text{l}}^{ - 1}}$ stands true for $^{12}C$ and varies accordingly for others.