Why is it impossible for an element to have an atomic number of 110.5? a. atoms of an element have the same whole number of protons and neutrons

b. atoms of an element all have the same whole number of protons

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