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Atoms – Valence Electrons . Orbital Levels - Review. closest to nucleus – max 2 electrons 2 nd shell – max 8 electrons 3 rd shell – max 8 electrons fill shells closest to nucleus first. Knowing how electrons are arranged in an atom is Important!
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Orbital Levels - Review • closest to nucleus – max 2 electrons • 2nd shell – max 8 electrons • 3rd shell – max 8 electrons • fill shells closest to nucleus first
Knowing how electrons are arranged in an atom is Important! Electrons control how atoms react with each other! H H O
HAPPY ATOMS Atoms want their outer most shell to be full and will lose or gain extra electrons to achieve that… Electrons on the outer most orbital have a special name: ValenceElectrons
Vocabulary Check: • Valence Electron – located on the outermost orbital (shell) • determine reactivity • same for all members of a group/family • Last digit of group # = # of valencee-
What does that have to do with anything?? Putting it all together
Sodium 1 - - - - - - - - - - - 1 H Hydrogen 1 3 Li Lithium 7 VALENCE 11 Na Sodium 23 NUCLEUS 19 K Potassium 39 37 Rb Rubidium 85
- - - - - - - - - - - - - - - - - 17 9 F Fluorine 19 Chlorine How many Valence Electrons? 17 Cl Chlorine 35 35 Br Bromine 80 NUCLEUS 53 I Iodine 127 85 At Astatine 210
- - - - - - - - - - - - - - - - - - - - - - - - - - - - Sodium Chloride“SALT” Chlorine Sodium NUCLEUS NUCLEUS
Journal Questions • Define Valence Electron. • What is the significance of valence electrons? • Use your periodic table to figure out how many valence electrons Magnesium has. Explain Magnesium’s reactivity using it’s valence number.