Stillwagon Test 2 Electrons & Bonding

metalloids on table

- divide periodic table along zig zag

- diagonal, down over, down over, diagonal

principle quantum #

n= any pos integer value

- (2n)^2 = # of e- per energy level

- describes energy level of e- (1-7)

angular momentum quantum number

l < or = n-1

- indicates shape of the electron's orbital

s: sphere

p: figure 8

d: clover

f: tetrahedral

magnetic quantum number

m = values from l to -l (if l=2 m could = 2, 1, 0, -1, -2)

- describes shape of orbital in 3D around axes (x, y, z)

- indicates the orientation of the orbital around the nucleus

s: 1 orientation

p: 3 orientations

d: 5 orientations

f: 7 orientations

EACH ORIENTATION CAN HOLD MAX 2 ELECTRONS!!!

spin quantum number

- ms = 1/2 or -1/2

- indicates the spin orientation (+/- 1/2) of an electron in an orbital

- 2 e- in same orientation must spin in different directions (pos is upwards, neg is downwards)

Aufbau Principle

electrons occupy the orbitals of lowest energy levels first

Pauli Exclusion Principle

- NO 2 ELECTRONS CAN BE IN SAME PLACE AT SAME TIME

- orbital may only contain 2 e- each w opposite spin directions

(no two electrons in the same atom can have the same set of four quantum numbers)

Hund's Rule

e- will fill up each orientation once before pairing up

cations and anions

cations gain e-, anions lose e-

how many VSEPR models are there?

6 (or 5 with bent having 2 possible bond angles)

linear

bond angle 180 degrees

bent 1 pair

IF 1 PAIR OF LONE ELECTRONS:

- bond angle 120 degrees

bent 2 pairs

IF 2 PAIRS OF LONE ELECTRONS:

- bond angle 105 degrees

trigonal planar

3 bonds, 0 lone pairs, bond angle 120 degrees

trigonal pyramidal

3 bonds, 1 lone pair, bond angle 107 degrees

tetrahedral

bond angle 109.5 degrees

Sheilding

core electrons partially block the attraction between the nucleus and the valence electrons

Periodicity

the repeating patterns of chemical and physical properties of the elements moving down/across periodic table

atomic radius

- 1/2 distance between 2 nuclei in molecule with identical atoms

- gets bigger as you go down (energy levels increase size)

- gets smaller as you go across (adds p+, force becomes strong)

ionization energy

- energy required to lose e-

- gets smaller as you go down table (shielding makes losing e- easier)

- gets bigger as you go across table (harder to lose e- closer you are to 8)

Electronegativity

- the ability of an atom to attract shared electrons when the atom is in a compound

- gets smaller going down table

-gets larger going across table (nonmetals want to attract e-)