What Is an Element? — Definition & Overview

Yes, two atoms cannot have the same number of neutrons, so these are the same element.

Yes, the extra neutron accounts for the difference in mass, meaning they have the same number of protons.

No, the extra neutron changes the identity of the atom since atoms are defined by the number of neutrons

No, the extra neutron accounts for the difference in mass, meaning they have the same number of protons.