Why is it impossible for an element to have an atomic number of 110.5?

Question

a. atoms of an element have the same whole number of protons and neutrons

b. the atomic number is the number of protons, which is always a whole number

c. exactly half of the isotopes would need an atomic number of 110 and half would need an atomic number of 111 which is very unlikely

d. atoms with atomic numbers greater than 100 are unstable

Answer 1

The correct answer is b. the atomic number is the number of protons, which is always a whole number.

The atomic number of an element is defined as the number of protons in the nucleus of an atom, and protons are whole particles. Therefore, it is impossible for an element to have a non-integer atomic number like 110.5.