Unit 1 Atoms Study Guide Know the 3 parts of an atom and their charges. Name Charge How to determine the number Location What causes an atom to become neutral? Can you identify an atom if you are given the number of protons, neutrons, and electrons? How many electrons can each shell hold? How many protons are found in Gold? What is gold’s mass number? How many neutrons does gold have? How many protons are found in Iron? What is iron’s mass number? How many neutrons does iron have? How many protons are found in Lead? What is lead’s mass number? How many neutrons does lead have? What is an isotope? Nitrogen-14 has how many protons, neutrons, and electrons? Nitrogen-17 has how many protons, neutrons, and electrons? Atomic Structure Timeline Be familiar with Democritus, Dalton, Thomason, Rutherford, and Bohr. What did they contribute to the knowledge we have about an atom, Be prepared to discussion Rutherford's Gold Foil Experiment.