If two atoms have a nucleus containing the same number of protons but a different number of neutrons, what is true? they are different isotopes of different elements. they are different elements but the same isotope. they are the same isotopes of the same element/ they are different isotopes of the same elements.

Option (d) is the correct answer.

Explanation:

Same elements that have different mass number but same atomic number are known as isotopes.

For example, and are isotopes.

As it is known that mass number means sum of total number of protons and neutrons. Whereas atomic number means the total number of protons only.

Isotopes have same number of protons but different number of neutrons.

On the other hand, different elements that have same atomic mass but different atomic number are known as isobars.

For example, and are isobars.

Thus, we can conclude that if two atoms have a nucleus containing the same number of protons but a different number of neutrons, then it is true that they are different isotopes of the same elements.

b.

the accuracy of the data.