Covalent bonding is electron _________
sharing
Covalent bonding occurs because the bonding atom’s elctronegativities are very ______
close
Covalent bonding does not form _____, it forms ______
Ions, molecules
Covalent bonds are formed between __________
non-metals
Shared electrons are called _______, excess electrons are called _________
bonding pair, lone pairs
How to draw a covalent compound (Lewis Dot)
1) Add up the # of valence electrons in the compound
2) Draw atoms with bonds between them
3) Determine which elements require additional electrons
What elements are drawn in the middle of covalent compounds?
Elements with the lowest EN; listed first
(Exception: H)
Sigma bonds
line directly connecting two atoms; 1st bonding pair/single bonds
Pi bonds
indirect/overlapping bonds connecting atoms
VSEPR
Valence Shell Electron Pair Repulsion - used to determine 3D shape of molecules
How do you determine electron geometry?
look at how many electron regions surround the central atom
2 electron regions (electron geometry and bond angle)–>
Linear, 180
3 electron regions (electron geometry and bond angle)–>
Trigonal Planar, 120
4 electron regions (electron geometry and bond angle)–>
Tetrahedral, 109.5
How to determine molecular geometry?
First determine electron geometry, then determine the number of lone pairs (VSEPR)
Trigonal Planar EG… possible Molecular Geometries?
0 lone pairs - trigonal planar
1 lone pair - bent
Tetrahedral EG… possible Molecular Geometries?
0 lone pairs - tetrahedral
1 lone pair - trigonal pyramidal
2 lone pairs - bent
How do you name a binary covalent compound?
1) Element w/ lower EN first
2) ending of the last element changed to -ide
3) apply proper prefixes
Prefixes…
Mono, di, tri, tetra, penta, hexa, hept, oct
Ex: if there is only one of the 1st written element, we do not put mono-
If there is no difference in EN, ______ will be formed
Non-polar covalent bond (same non-metals)
If there is medium difference in EN, ______ will be formed
Polar covalent bond (different non-metals)
If there is large difference in EN, ______ will be formed
ionic bond (metal and non-metal)
Polarity is _____
uneven charge distribution
Least polar type of bond, most polar
NPCB, IB