Atomic Structure: Isotopes and Ions
Isotopes The number of protons for a given atom never changes. The number of neutrons can change. Two atoms with different numbers of neutrons are called isotopes Isotopes have the same atomic # Isotopes have different atomic Mass # ’ s
Isotopes
Ions An atom that carries an electrical charge is called an ion If the atom loses electrons, the atom becomes positively charged. If the atom gains electrons, the atom becomes negatively charged
Ions The number of protons does not change in an ion. The number of neutrons does not change in an ion. So, both the atomic number and the atomic mass remain the same.
Example 1: Ca +2
Example 2: O -2
PEN Method for--- Li +1 Cl -1 U-238 Mg +2 F -1 S -2