M. Intersection 4. 9/26/06 Reading: 8.6 bond length p 348-351 8.10 exceptions p 363-366. The Cutting Edge Science at the Extent of our Knowledge Oct 9 th 6:00 – 7:30 PM Information Storage: DNA and Transistors Attendance Optional. M. Outline. Concept Questions Lewis Structures
Reading: 8.6 bond length p 348-351
8.10 exceptions p 363-366
The Cutting Edge
Science at the Extent of our Knowledge
Oct 9th 6:00 – 7:30 PM
Information Storage: DNA and Transistors
What is the approximate number of carbon atoms it would take placed next to each other to make a line that would cross this dot: •
Following is a list of properties of a sample of solid sulfur:
Which, if any, of these properties would be the same for one single atom of sulfur obtained from the sample?
C 12.011 g/mol (*1)
H 1.007 g/mol (*4)
CH4 16.039 g/mol
Which of the following are true about 18.013 grams of water H2O :
a) Contains 2 hydrogen atoms and 1 oxygen atom
b) Contains 2 moles of hydrogen atoms and 1 mole of oxygen atoms
c) Contains 1 mole of water molecules
d) Is 66.7% hydrogen by weight
e) Contains 6.02 x1023 water molecules
Which of the following samples could be methane, CH4? A sample that contains:
(a) 25% hydrogen by weight; 75% carbon by weight
(b) 4.0 g of H atoms and 1.0 g of C atoms
(c) 0.40 mole of H atoms and 1.0 x 1023 C atoms
(d) 0.40 mole of H2 molecules and 0.20 moles of C atoms
True or False? When a match burns, some matter is destroyed.
What is the reason for your answer to question 3?
Formal charge = # valence electrons -# assigned electrons
Count valence electrons:
H 3 * (1) = 3
O 1 * (6) = 6
8 valence e-
Nonbonding electrons + 1 e- from each bond
Sum of formal charges = charge of molecule
Note: Usually central atom is least electronegative
16 valence e-
N 3.0; S 2.5
An expanded octet can be achieved with atoms that have d-orbitals in their valence shell.
You must have an atomic orbital in the valence shell for every bond that you make.
You may not use all valence atomic orbitals to make a bond (ex, borane, water, sulfur hexafluoride.)