* Protons: 58
* Electrons: 58 (in a neutral atom)
* Neutrons: This varies depending on the isotope. The most common isotope, Cerium-140, has 82 neutrons.
Explanation:
* Atomic Number: The atomic number of an element defines the number of protons in its nucleus. Cerium has an atomic number of 58, so it has 58 protons.
* Electrons: In a neutral atom, the number of electrons always equals the number of protons to balance the charges.
* Neutrons: The number of neutrons can vary within an element, creating different isotopes. The mass number of an atom (protons + neutrons) identifies the specific isotope. The most common isotope of Cerium, Cerium-140, has a mass number of 140. To find the number of neutrons, subtract the atomic number (58) from the mass number (140): 140 - 58 = 82 neutrons.
