Two atoms A and B have the following nuclear composition: Atom A Atom B 17 protons 17 protons 18 neutrons 20 neutrons 17 electrons 17 electrons a) What is the mass numbers and atomic numbers of A and B. b) What is the relation between the two chemical species? c) which element or elements do they represent?



A) atomic numbers:
* atom A: 17, atom B: 17
mass numbers:
* atom A: 35, atom B: 37
b) both of the atoms are isotopes
c) both atoms represent the element chlorine with its isotopes Cl35 and Cl37