All isotopes of the same element have ________ A. Different atomic numbers and different atomic mass B. Different atomic numbers and the same atomic mass C. The same atomic number but different atomic masses D. The same atomic number and the atomic mass

The correct answer is: C. The same atomic number but different atomic masses.

An isotope is a form of an element that has the same number of protons in its nucleus but different numbers of neutrons. The number of protons determines the chemical element, and the number of neutrons determines the isotope. Isotopes of the same element have the same atomic number but different atomic masses.

For example, carbon-12 has 6 protons and 6 neutrons, while carbon-14 has 6 protons and 8 neutrons. Both carbon-12 and carbon-14 are isotopes of carbon, but they have different atomic masses.

Isotopes are important because they can be used to trace the movement of elements through the environment. For example, carbon-14 is used to date archaeological artifacts.