LM21-22 Flashcards
Lewis dot structures for compounds must have ______
a central atom placed in the center of perimeter atoms
Which atoms’ outer shells should be filled first when making a Lewis dot structure?
Perimeter atoms
Formula for number of shared electrons in a covalent compound
N (needed electrons) - A (available electrons)
The central atom is most often the atom with the ________ electronegativity
least
A cation’s Lewis dot model will have _____ electrons
0
Steps to drawing a Lewis dot structure for a compound
Lay out atoms in arrangement, add valence electrons, fill perimeter shells, add the rest to central atom, make bonds to satisfy central atom
Resonance
A compound that has multiple places where a double bond can be placed
Resonance is common in what numbers of bonds/locations?
3 bonds, 2 locations; 4 bonds, 3 locations
Delocalization
Not one fixed atom will be the one to share an extra bond in resonance structures
Resonance is common in what 4 compounds?
Nitrite, ozone, nitrate, carbonate
Resonance explains equal bond lengths because….
it equally distributes the electron density amongst the resonance structures rather than concentrating it on one bond
Hypovalent
An atom in a compound fills up less than 8 electrons
Elements that commonly are hypovalent (and why)
Boron and beryllium (2A and 3A), they do not reach 4 electrons
Hypervalent
An atom in a compound fills up more than 8 electrons
Elements that commonly are hypervalent (and why)
below second row (n=3 and up), due to d orbital
