Final answer:
The atom of element A would have an atomic number of 23 since the atomic number is equivalent to the number of protons in an atom's nucleus.
This number defines the chemical element and determines its identity. By comparison, uranium has an atomic number of 92 and thus, 92 protons.
Step-by-step explanation:
An atom of element A with 23 protons would have an atomic number of 23. This is because the atomic number is defined as the number of protons in an atom’s nucleus, and it uniquely identifies the chemical element.
For example, any atom with 6 protons is known as carbon and has an atomic number of 6. An element's atomic number also tells you the number of electrons in a neutral atom of that element.
In relation to other elements, the atomic number of uranium is 92, indicating it has 92 protons. For an isotope of uranium with a mass number of 235, the number of neutrons would be the mass number minus the atomic number, which is 235 - 92, equating to 143 neutrons.