Why is it impossible for an element to have an atomic number of 110.5? (1 point)

Responses

Atoms with atomic numbers greater than 100 are unstable.
Atoms with atomic numbers greater than 100 are unstable.

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

​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.
​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.

Atoms of an element all have the same whole number of protons and neutrons.

1 answer

The correct response is:

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

The atomic number represents the count of protons in the nucleus of an atom, and since protons are discrete particles, the atomic number must be a whole number.