Final answer:
Every atom of chromium, including chromium-58, has 24 protons, as indicated by its atomic number.
Step-by-step explanation:
The number of protons in an atom is defined by its atomic number. For the element chromium (Cr), the atomic number is 24. This means that every atom of chromium, regardless of its mass number, will always have 24 protons. Consequently, chromium-58 would also have 24 protons in its nucleus.