Claim: In their atomic nuclei carbon all has the same number of protons.
Evidence: Carbon -LRB- from carbo `` coal '' -RRB- is a chemical element with symbol C and atomic number 6.
The atomic number or proton number -LRB- symbol Z -RRB- of a chemical element is the number of protons found in the nucleus of an atom.
The atomic number uniquely identifies a chemical element.