Answer:
B) Gold
A) Number of electrons and protons.
Step-by-step explanation:
Atomic Masses (from periodic table):
----> Copper (Cu): 63.546 g/mol
----> Gold (Au): 196.97 g/mol
----> Iron (Fe): 55.845 g/mol
----> Platinum (Pt): 195.08 g/mol
The atomic number represents the number of protons. Neutral atoms have the same number of protons as electrons. The mass number represents the number of protons and neutrons.