Question

The mass number of an atom is equal to _____.

the atomic mass of an element.

the atomic number of an element.

the sum of the number of protons and the number of neutrons per atom.

the sum of the number of neutrons and the number of electrons per atom.

None of the above

Answer 1

The mass number of an atom is equal to the sum of the number of protons and the number of neutrons per atom.

The mass number is almost equal to the atomic mass of a particular atom. Therefore it can be written as:

Mass no. of an atom = No. of protons + No. of neutrons.