Question

The value of one atomic mass unit (1 u) is:

Options

• \[1.00727 \times 10^{-27}~\mathrm{kg}\]

• \[1.67262 \times 10^{-27}~\mathrm{kg}\]

• \[1.6749 \times 10^{-27}~\mathrm{kg}\]

• \[1.660539 \times 10^{-27}~\mathrm{kg}\]

Answer 1

The atomic mass unit is defined as one-twelfth of the mass of a carbon-12 atom, giving \[1~\mathrm{u} = 1.660539 \times 10^{-27}~\mathrm{kg}\]. Note that \[1.67262 \times 10^{-27}~\mathrm{kg}\] is the proton mass and \[1.6749 \times 10^{-27}~\mathrm{kg}\] is the neutron mass.