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