Protons in different elements with the same atomic number are not different. The atomic number of an element represents the number of protons in the nucleus of an atom, and it uniquely identifies that element. All atoms of a given element have the same number of protons in their nuclei, which is what distinguishes one element from another.
For example, carbon has an atomic number of 6, which means that all carbon atoms have 6 protons in their nuclei. Whether it is a carbon atom in a diamond or a carbon atom in a molecule of carbon dioxide, they all have 6 protons.
While different elements may have the same number of protons, they differ in their number of neutrons and electrons, which affects their atomic mass and chemical properties. The isotopes of an element have the same atomic number but different atomic masses due to varying numbers of neutrons. However, the atomic number remains constant within a specific element, defining its identity and determining its place in the periodic table.