0. Ions & Isotopes!

1. IONS Ion = charged An atom typically has a neutral charge, but….
When atoms GAIN or LOSE electrons, they become charged IONS!

2. ISOTOPES Isotope = same element with different numbers of NEUTRONS!
Atomic Mass = an average…you find it by adding the number of protons (which never changes) PLUS the number of neutrons….which can change
For example, most atoms of Argon have 22 neutrons, but some only have 21 neutrons

3. But what about…
So, if atoms gain or lose electrons they become IONS…
And if atoms gain or lose neutrons, they become ISOTOPES…
Atoms do not “gain” or “lose” protons…b/c if they did, they’d become COMPLETELY different ELEMENTS!
Remember, an atom’s # of protons is it’s identity

4. Ion, Isotope, or completely different Element?
Protons = 33
Electrons = 33
Neutrons = 42
Protons = 34
Electrons = 34
Neutrons = 47 As Se

5. Ion, Isotope, or completely different Element?
Protons = 36
Electrons = 36
Neutrons = 48
Protons = 36
Electrons = 36
Neutrons = 47 Kr Kr

6. Ion, Isotope, or completely different Element?
Protons = 9
Electrons = 9
Neutrons = 10
Protons = 9
Electrons = 10
Neutrons = 10 F F-

7. Ion, Isotope, or completely different Element?
Protons = 19
Electrons = 19
Neutrons = 20
Protons = 19
Electrons = 18
Neutrons = 20

8. one last thing…
Metals tend to LOSE electrons in chemical reactions, forming POSITIVE ions
Nonmetals tend to GAIN electrons in chemical reactions, forming NEGATIVE ions…