Unit 3: Atomic Structure Flashcards
(57 cards)
Rutherford:
Gold foil experiment w/alpha particles.
An atom consists of e moving around a dense + charged nucleus containing p.
Issues: e are constantly accelerating so they should eventually lose E and collapse into the nucleus.
Max Planck:
Analyzed blackbodies. He concluded that E is NON-continuous.
Blackbodies:
able to absorb/emit light @ a certain wavelength based on temp.
Quantum:
Small, discrete, indivisible quantity (burst = quantum of E)
Photoelectric effect:
ejection of an e can only happen when a min amnt of E from a photon is transferred to the e.
Photon:
Small packet of light E of a SPECIFIC frequency.
Bhor’s model:
e orbit nucleus in defined E states –> don’t collapse into nucleus. e can change their E by transitioning from on E state to another. so… e can only have certain allowed values –> quantized! Based his model on line spectra of H+.
LIMIT: Couldn’t explain line spectra for elements other then H+.
Louise de Broglie:
Stated that all matter has wavelike properties (found that the radius of orbit = # of wavelengths)
Erwin Schrodinger:
used math to explain that electrons have wavelike natures. Suggests that emission spectra results from e TRANSFORMING from one orbital to another.
Atomic orbital:
Predict the space where there is a high probability of finding an e in an atom = quantum mechanical atomic model.
Uncertainty principle (heisenberg):
position and speed of e cant be known w/certainty.
electron configuration:
e are arranged based on E lvls (don’t occupy orbits but ORBITALS)
n = principal
describes size. MAX amount of e in E lvl = 2n^2
Look at the e and the element, and based n on what period its in.
n = 1 @ ground state.
I = angular moment quantum number
describes shape. Values depend on n.
s-orbital: I = 0 (holds 2 e)
p-orbital: I = 1 (3 orbitals, w/2 e)
d-orbital: I = 2 (5 orbitals, w/2 e)
f-orbital: I = 3 (7 orbitals, w/2 e)
mi = magnetic quantum number
specifies orientation. depend on I.
draw orbital diagrams depending on the I value (like if I = 1, then its in the p orbital so 3 boxes) and draw arrows based on the configuration (so like if its 1s22s22p23s23p2, then it would have 2 arrows w/one in each box cuz 3p has 2)
ms = magnetic spin number
determines e spin. can be +-1/2
Based off of which direction arrow is in the orbital box drawing.
Pauli exclusion principle:
no 2 electrons can have the same values for n,I,mI,ms.
Aufbau Principle:
e are added to an atom one at a time; each to the lowest E orbital avail.
Shorthand e configurations:
Uses the preceding noble gas in place of the e configuration for the # of e in the noble gas.
EX:
Ar = 1s2 2s2 2p6 3s2 3p6
= [Ne] 3s2 3p6
Hunds rule:
the most stable arrangement of e in the same sub-shell has the max # of unpaired e w/same spin.
Expanded e configuration:
shows a list of EACH occupied orbital.
EX:
N = 1s2 2s2 2p3
N = 1s2 2s2 2p1 2p1 2p1
Orbital box diagram:
shows each occupied orbital and the e spins (arrows and boxes).
Exceptions w/transition metals:
contain occupied d orbitals filled AFTER the s orbital.
EXCEPTION:
- half fill or fill the (n-1)d orbital first, ns can be left HALF FILLED.
Cations and Anions e config:
Cations: lose an e
EX: Li = 1s2 2s1
Li+ = 1s2 = [He]
Anions: gains e
EX: O = 1s2 2s2 2p4
O2- = 1s2 2s2 2p6 = [Ne]
