Scientists now know that most elements come in more than one version. The different versions are called . The difference between them is the number of neutrons in the nucleus.

Isotopes

Explanation:

Scientists now know that most elements come in more than one version. The different versions are called Isotopes. The difference between them is the number of neutrons in the nucleus.

Isotopes usually differ in the mass number of the elements which is the reason why they also have a different neutron number. They may also differ in physical characteristics but would most likely have common chemical properties.

idk

explanation:

first one is the correct answer