Electron Dot StructuresLewis Dot Structure
Same, Same
Learning Target
• Learning Target 1.3: Draw accurate models of atoms and compounds
• Learning Target 1.3b: Draw Lewis Dot Structures for atoms and compounds
• This PPT focuses on drawing Lewis Dot Structures for ATOMS• Drawing LDS for compounds comes later
Lewis vs Bohr
• Bohr Models show the Protons, Neutrons and ALL the electrons
• Lewis structures just show the atomic symbol and VALENCE (outermost shell) electrons
Be
Lewis vs Bohr
• Look at these Bohr models• How many VALENCE electrons does each one possess?
H
Li
Na
K
Hmmm. I thinks Isees a pattern…
Lewis vs Bohr
• Look at these Bohr models• Every atom in Group 1 has ONE valence electron
H
Li
Na
K
Lewis vs Bohr
• Look at these Bohr models• Every atom in Group 2 has TWO valence electrons
Be
Mg
Ca
Lewis vs Bohr• In this “pattern”, skip over
these elements (transition metals), they behave differently
12 3 4 5 6 7
8
Group number corresponds withthe number of valance electrons
So, there’s actually a system in the organization of
the periodic table?
Bohr Lewis
Shows protonsShows neutronsShow ALL electronsShows ALL shells
Show VALENCE electronsShows VALENCE shellsShow electrons
Drawing Lewis Dot Structures (LDS) orElectron Dot Structures (EDS) orElectron Dot Diagram (EDD)Same, Same. Same, Same. So, this one of those “easy”
things that is actually easy? I’m skeptical…
Practice
• Check the “Target 1.3a Practice” PPT for videos and practice