Write isotopic symbols in the form X-A (e.g., C-13) for each isotope. d. the uranium isotope with 143 neutrons

Key Concepts

Isotopes

Isotopes are variants of a chemical element that have the same number of protons but different numbers of neutrons. This difference in neutron count results in varying atomic masses for the isotopes of the same element. For example, carbon has isotopes like carbon-12 and carbon-14, where the numbers indicate the total number of protons and neutrons.

Isotopic Notation

Isotopic notation is a way to represent isotopes using the format X-A, where X is the chemical symbol of the element and A is the mass number (the sum of protons and neutrons). For instance, in the notation C-13, 'C' stands for carbon and '13' indicates that this isotope has a total of 13 nucleons. This notation helps in identifying specific isotopes and their properties.

Mass Number

The mass number of an isotope is the total count of protons and neutrons in its nucleus. It is crucial for determining the identity of an isotope and is used in isotopic notation. For example, if a uranium isotope has 143 neutrons and uranium has 92 protons, its mass number would be 235, leading to the notation U-235.