Argon has three naturally occurring isotopes, with mass numbers 36, 38, and 40.
c. How are they different?

Verified step by step guidance

1. Understand the concept of isotopes: Isotopes 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 different mass numbers for the isotopes.
2. Identify the isotopes of argon: The problem states that argon has three naturally occurring isotopes with mass numbers 36, 38, and 40. These mass numbers represent the sum of protons and neutrons in the nucleus of each isotope.
3. Determine the proton count: Argon is element number 18 on the periodic table, meaning all isotopes of argon have 18 protons. This is a defining characteristic of the element argon.
4. Calculate the neutron count for each isotope: Subtract the number of protons (18) from the mass number of each isotope to find the number of neutrons. For example, Argon-36 has 36 - 18 = 18 neutrons, Argon-38 has 38 - 18 = 20 neutrons, and Argon-40 has 40 - 18 = 22 neutrons.
5. Summarize the differences: The isotopes of argon differ in their number of neutrons, which leads to differences in their mass numbers. This variation does not affect their chemical properties significantly, as chemical behavior is primarily determined by the number of protons and electrons.

Key Concepts

Isotopes

Isotopes are variants of a particular chemical element that have the same number of protons but different numbers of neutrons. This difference in neutron count results in varying mass numbers, which can affect the stability and radioactive properties of the isotopes. For example, argon has isotopes with mass numbers 36, 38, and 40, indicating they each have 18 protons but differ in neutron count.

Mass Number

The mass number of an isotope is the total count of protons and neutrons in its nucleus. It is a crucial identifier for isotopes, as it distinguishes them from one another. In the case of argon, the mass numbers 36, 38, and 40 indicate the total number of nucleons, which influences the isotope's physical and chemical properties.

Stability of Isotopes

The stability of isotopes refers to whether an isotope is stable or radioactive. Stable isotopes do not undergo radioactive decay, while unstable isotopes do, leading to the emission of radiation. For argon, the isotopes with mass numbers 36 and 40 are stable, while argon-38 is less common and can be radioactive, affecting its applications in fields like radiometric dating and atmospheric studies.