How does the notation uranium-235 identify a specific uranium isotope?

The notation uranium-235 identifies a specific isotope of the element uranium by combining the element's name with its mass number.12

In chemistry and nuclear physics, all atoms of a given element possess the same number of protons, known as the atomic number. For uranium, this number is 92. However, isotopes of the same element differ in the number of neutrons within their nuclei. The mass number (represented by the symbol A) is the sum of the protons and neutrons present in the nucleus.231

By specifying "235," the notation indicates that this particular uranium atom has a total of 235 protons and neutrons. Specifically, uranium-235 contains 92 protons and 143 neutrons. This distinguishes it from other isotopes, such as uranium-238, which has the same number of protons but a different number of neutrons (146), resulting in a different mass number.31