ap chemistry: unit 2 - Course

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Lexi Eyerman – AP CHEM SUMMARY
29 Sept. 2011
AP CHEMISTRY: UNIT 2 [pgs. 198-273, chapters 6-7]
I.
Scientific Laws, Theories, and BIG Ideas
a. The Wave Nature of Light
i. Electromagnetic Radiation – energy carried through space (ex/ light)
b. Dual-nature of Electrons & Photons
i. Quantized Energy: Planck’s Constant (see Equations section); only a
certain fixed quanta of energy is emitted (one/ a few fixed
wavelengths)
ii. Photoelectric Effect: light can be particle-like (photons)
iii. Electrons have energy and frequencies associated with them and
require a certain quanta of energy to change energy levels.
c. Electrons
i. Energy is negative and becomes less negative as you go outward
ii. Writing electron configurations:
1. n = size of path (Principle Quantum Number, a.k.a. P.E.L)
2. l = shape of path (0=s, 1=p, 2=d, 3=f); n-1 = l
3. m = orientation of path (m= -l… +l)
4. ms = electron spin
iii. No two electrons can have the same set of quantum numbers
iv. Hund’s rule: draw spin up before spin down
v. No more than 2 electrons per orbital
vi. Magnetic properties
1. Ferromagnetism – unpaired electrons attracted into magnetic
field
2. Paramagnetism – unpaired electrons attracted into magnetic
field (induced; ex/ Al, Mn, Sc, Y, lanthanides)
3. Diamagnetism – all electrons are paired; no attraction to
magnetic field (noble gases)
d. Periodicity
i. Effective nuclear charge – the number of protons in nucleus minus the
avg. number of electons between the nucleus and electron in question
1. Coulomb’s law: attraction affected by difference in charge and
distance/ size
ii. Cation: positive; size = smaller; anion = negative; size = larger
iii. Isoelectronic series = ions that have same number of electrons
iv. First Ionization energy = energy required to remove first electron
from a neutral atom
v. Electronegativity = electron affinity; the attraction of an atom for an
electron
vi. Groups/ Types of elements
Lexi Eyerman – AP CHEM SUMMARY
29 Sept. 2011
1. Metals = majority of elements; shiny; conduct heat &
electricity; malleable, ductile, solids at room temp; reducing
agents
a. Alkali: group 1; react violently with water
b. Alkaline Earth: group 2; react with water
2. Nonmetals = poor conductors of heat and electricity; diatomic
(7H club); oxidizing agents
a. Halogens: group 7
3. Metalloids = in-between metals & nonmetals
Ionization Energy decreases
Electronegativity decreases
= nonmetals
= metals
= metalloids
= Lanthanide series
= Actinide series
II.
Ionization Energy increases
Electronegativity increases
Equations & Calculations
๐‘š
a. Speed of light = c = 3.00 × 108 ๐‘  ; use in wavelength & frequency calc
(below);
b. ๐‘ = ๐œ†๐œˆ ; c= speed of light, ๏ฌ = wavelength (m); ๏ฎ = frequency (hertz = 1/s)
i. Wavelength and frequency are indirectly related
ii. Speed remains constant
c. ๐ธ = โ„Ž๐œˆ ; E= energy, h = Planck’s constant (6.63 × 10−34 ๐ฝ โˆ™ ๐‘ ); ๏ฎ = frequency
i. Used to determine energy of a photon of a certain ๏ฌ or ๏ฎ
ii. Direct relationship between frequency and energy
๐‘„ ๐‘„
d. Coulomb’s law: ๐น = ๐‘˜ ๐‘Ÿ1 2 2 ; F=force, k= a constant, Q = charge, r = distance
i. Used to determine attraction: positive = repulsive, negative =
attractive force
1
e. ๐ธ = (−2.18 โˆ™ 10−18 ๐ฝ)(๐‘›2 ) ; E = energy; n = principle energy level
i. Used to determine energy of an electron in a certain state
1
1
f. โˆ†๐ธ = (−2.18 โˆ™ 10−18 ๐ฝ)(๐‘›2
− ๐‘›2
); nfinal = final P.E.L. of electron
๐‘“๐‘–๐‘›๐‘Ž๐‘™
๐‘–๐‘›๐‘–๐‘ก๐‘–๐‘Ž๐‘™
i. Used to determine the amount of energy released/ absorbed when an
electron is moving into/ out of an excited state
ii. Negative = energy released; positive = energy absorbed
III.
Favorite Topic: The Periodic Table – I like to see the relationship between
different elements and like to pick out patterns.
Lexi Eyerman – AP CHEM SUMMARY
IV.
29 Sept. 2011
Least Favorite Topic: Magnetism – it seemed random and unrelated.
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