How do structures of atoms Differ? Protons = the atomic # of an element Protons give the element it’s identity Protons are given the identity Z number Identify each element Z=2, Z=45, Z=23 Isotopes are atoms of an element with the same # of protons, but different # of neutrons. The Mass number is the number of protons + the number of neutrons. Mass # is given the identity A number
How do structures of atoms differ? Isotopic Symbol A Z A = Mass # (p+n) Z = atomic # (p) A-Z= # of neutrons X is the element’s symbol from the periodic table
Section 2 A Guided Tour of the Periodic Table Chapter 4 Isotopes