one neutron is added to the nucleus of an atom of Carbon-12. how has the atom been changed?

It has a greater atomic mass?

Yes, the mass is greater, the atomic number stays the same (so it's still carbon) but it is an isotope of carbon; i.e., carbon 12 and carbon 13 are isotopes of carbon.

Thank you!

Yes, adding one neutron to the nucleus of an atom of Carbon-12 would result in a change in the atom's mass. Carbon-12 normally has 6 neutrons, but adding one neutron would increase the total number of neutrons to 7. This would create a new isotope called Carbon-13, which has an atomic mass of approximately 13 atomic mass units (AMU). Therefore, the atom has been changed by increasing its atomic mass from 12 AMU to 13 AMU.

Yes, by adding one neutron to the nucleus of an atom of Carbon-12 (which normally has 6 protons and 6 neutrons), the atom is changed. The addition of the neutron increases the mass of the atom, but it does not change its atomic number.

The atomic number of an atom is determined by the number of protons it has. In the case of Carbon-12, it has 6 protons, so its atomic number is 6. Adding a neutron does not change the number of protons, so the atomic number remains the same.

However, the mass number of an atom is determined by the total number of protons and neutrons in its nucleus. Normally, Carbon-12 has 6 neutrons (together with 6 protons), so its mass number is 12 (6 protons + 6 neutrons = 12). By adding a neutron, the new atom would have 7 neutrons. Therefore, the mass number of the atom would be 13 (6 protons + 7 neutrons = 13).

In summary, the addition of one neutron to the nucleus of a Carbon-12 atom increases its mass number from 12 to 13, while its atomic number remains 6.