Basic review
How do we calculate atomic # and mass #?
Atomic number = number of protons
Mass # = # of protons + # of electrons
Which principle states “atomic orbitals are filled from lowest to highest potential energy”?
Aufabu principle
Define electronegativity.
Differences in electronegativity in bonded atoms leads to _____ ______ bonds.
The tendency for an atom to attract electrons in order to reach an octet and thus become a more stable base.
Differences in electronegativity in bonded atoms leads to _polar__ _covalent___ bonds.
What is the difference in ionic vs covalent bonds in terms of the electron?
Ionic bonds = giving away electrons to fill octet
Covalent bonds = sharing of electrons to fill octet
Draw the electronegativity trend in the periodic table.
What are the most & least electronegative atoms on the periodic table?
Going down row = higher EN, Going down column = higher EN
Most - F Least - H
Metals tends to ___ electrons. Non-metals tend to _____ electrons.
Metals tends to __lose__ electrons. Non-metals tend to __gain___ electrons.
Which theory states that “atoms have an internal structure consisting of 1 or more subatomic particles”?
List the 3 subatomic particles and their charge.
Modern atomic theory
neutrons, protons (+), electrons (-)
What are the 2 ways we represent electronegativity differences in a polar covalent bond?
S- & S+ or +-->
List the normal number of covalent bonds for the following:
Hydrogen, Nitrogen, Oxygen, Carbon
List the normal number of lone pairs for the following:
Carbon, Nitrogen Oxygen, Halogens
List the normal number of covalent bonds for the following:
Hydrogen - 1
Nitrogen - 3
Oxygen - 2
Carbon - 4
List the normal number of lone pairs for the following:
Carbon - 0
Nitrogen - 1
Oxygen - 2
Halogens - 3
What are the 4 factors involved in quantum numbers?
Spins, orbitals, sublevels, main energy levels
What is formal charge? How do we calculate it?
Formal charge = the charge of atom after it has undergone a reaction
Valence electrons - (lines + dots) = formal charge
Define Heisenberg's uncertainty principle.
we cant predict the exact location of an electron; only the general area it is in (orbitals)
No difference in electronegativity in bonded atoms leads to __- ____ ______ bonds.
No difference in electronegativity in bonded atoms leads to _non__- __polar____ __covalent_____ bonds.
Which bond is ALWAYS non-polar EXCEPT when bonded to a polar covalent bond?
C-H
Fill in table 1 (shown in session).
Answer shown in session
Define wave function and atomic orbitals.
Wave fx= the fact that electrons move in waves
atomic orbitals= general area electrons surround the nucleu
Which principle states “No 2 electrons can have identical quantum numbers; each atomic orbital can have a maximum of 2 electrons”?
Paulis expression principle
Define the octet rule and its importance in lewis structures.
Octet rule is when an atom wants to fill its valence shell (which requires 8 e-s); lewis structures tell us how many valence electrons an atom has and allows us to predict reactions (such as acid base rxs)
T/F: polar molecules are symmetrical. Explain.
False- The asymmetric pull of electrons makes them polar
How many electrons can each energy level hold?
How many electrons can each sublevel hold?
How many electrons can each orbital hold?
1. N = 1 - 2e- N = 2 - 8e- N = 3 - 18e- N = 4 - 32e-
2. S = 2 e- P = 6e- D = 10e- F = 14e-
3. 2e-
Define degenerate orbitals.Give an example.
Orbitals that are in the same sublevel but different orientation in space; px,py,pz
Define Hund’s rule. (Hint: think stability)
the more unpaired electrons within an electron configuration (unpaired spins), the more stable the molecule due to less repulsion
How many orbitals in each energy level?
How many orbitals in each sub-level?
N = 1 - 1 orbital N = 2 - 4 orbitals N = 3 - 9 orbitals N = 16 orbitals
S =1 P = 3 D = 5 F = 7
Define kekule, condensed, and lewis structures.
Kekule - all bonds no lone pairs
Condensed - written formula
Lewis - bonds and valence e-
What are the 5 rules in writing condensed structures?
All atoms bonded to carbon are written to the right of the carbon they are bonded to
Multiple of the same group in a row can be written with a subscript in parenthesis
Groups bonded to the last carbon do not need parenthesis
Groups hanging from a carbon can be written in parentheses
Groups bonded to the first carbon can be written in parentheses to the left of that carbon