Which of the following statements about isotopes is true?
Isotopes are a fascinating topic in the field of chemistry and physics. They are atoms of the same element that have the same number of protons but different numbers of neutrons. This difference in neutron count results in isotopes having different atomic masses and, in some cases, different chemical properties. In this article, we will explore some common statements about isotopes and determine which one is true.
Statement 1: Isotopes are always radioactive.
This statement is false. While some isotopes are indeed radioactive, not all of them are. Radioactivity is a property of isotopes that have an unstable nucleus, which means they undergo radioactive decay to reach a more stable state. However, many isotopes have a stable nucleus and are not radioactive. For example, carbon-12, which is the most abundant isotope of carbon, is stable and not radioactive.
Statement 2: Isotopes have the same number of protons.
This statement is true. Isotopes are atoms of the same element, which means they have the same number of protons in their nuclei. The number of protons determines the element’s identity. For instance, all isotopes of hydrogen have one proton, while all isotopes of carbon have six protons.
Statement 3: Isotopes have the same atomic mass.
This statement is false. Isotopes have different atomic masses due to the varying number of neutrons in their nuclei. The atomic mass is the weighted average of the masses of all the isotopes of an element. For example, carbon-12 has an atomic mass of 12, while carbon-13 has an atomic mass of 13, which is 1 atomic mass unit (amu) heavier than carbon-12.
Statement 4: Isotopes have the same chemical properties.
This statement is false. While isotopes have the same number of protons and electrons, which determines their chemical properties, the difference in neutron count can sometimes affect their chemical behavior. This is particularly true for isotopes with a large difference in neutron count, as they may exhibit different nuclear spin and magnetic properties. However, in most cases, isotopes of the same element have similar chemical properties.
Conclusion
In conclusion, out of the four statements about isotopes, the true statement is that isotopes have the same number of protons. This is the defining characteristic of isotopes and is what makes them belong to the same element. The other statements are either false or misleading, as isotopes can have different atomic masses, not always be radioactive, and sometimes exhibit different chemical properties. Understanding the unique properties of isotopes is crucial in various scientific fields, including chemistry, physics, and nuclear engineering.
