The table below shows the number of sub-atomic particles in an atom of sodium. sub-atomic particles sub-atomic particle number protons 11 neutrons 12 electrons 11 what is the amu of a sodium atom? 11 12 23 34

Answer is: the amu of a sodium atom is 23.

The unified atomic mass unit (amu) is a standard unit of atom mass.

One unified atomic mass unit is approximately the mass of one nucleon (proton or neutron).

The unified atomic mass unit is equal 1.66·10⁻²⁷ kg.

n(p⁺) = 11; number of protons in sodium atom.

n(n°) = 12; number of neutrons of sodium atom.

n(p⁺ + n°) = 11 + 12.

n(p⁺ + n°) = 23; number of nucleons in sodium atom.

the answer will be 23

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