Final answer:
The statement that all platinum (Pt) atoms have the same number of protons is true, as the number of protons defines an element's atomic number, which is 78 for platinum. Atoms may have different numbers of neutrons (isotopes) or gain and lose electrons (ions), but the atomic number remains constant.
The statement 'All platinum (Pt) atoms have the same number of protons' is true.
Step-by-step explanation:
The number of protons in an atom defines the element, and for platinum, this atomic number is 78. This characteristic is so fundamental that it is considered the atomic number (Z) of the element, which is unique to each element.
Atoms of the same element, such as platinum, will always have the same number of protons, but they may have different numbers of neutrons, leading to different isotopes. Nonetheless, the atomic number remains consistent. For instance, neutral atoms of platinum will have 78 protons, matching the number of electrons to maintain neutrality.
Occasionally, atoms may gain or lose electrons to become ions, represented with a '+' or '-' sign and these have significant roles in various chemical and biological processes. However, the number of protons, hence the identity of the element, remains unchanged in any form the atom takes.