AP Chem 14-15 Unit 2 Topics:
1.
Atomic Structure basics: a.
Critique atomic model based on evidence (ex: given thomson’s results then critique Dalton’s model; given Rutherford’s results to critique Thomson; etc..) b.
Subatomic particles: symbol, mass, charge, location in atom c.
Relate mathematically the connection between the atomic mass & molar mass using avogadro’s number
(mass of individual nuclear particles would be provided) d.
Isotopic Notation: mass number, atomic number, element symbol, charge e.
Create and/or interpret Mass Spectrometer graphs to determine common isotopes and the % abundance of these isotopes f.
Predicting/calculating weighted average atomic mass (WAAM) from relative abundances of isotopes
(usually given as %) AND predicting/calculating relative abundances of isotopes from WAAM
*WAAM: the weighted average atomic mass for the elements naturally found on Earth can be located on the periodic table g.
Interpretation of mass spectroscopy data/graphs (and, of course, what is being measured!)
2.
Coulombic Attraction a.
Qualitatively derive & interpret relationship between the force of attraction/repulsion and distance between the charged particles; force of attraction/repulsion and magnitude of charges of charged particles b.
Identify which coulombic factor (distance or magnitude of charges) plays a more influential role in the attraction between protons and electrons of an atom c.
Apply coulombic factors with atomic structure to justify periodic trends for first ionization energy & atomic radius (within a group, within a period, between multiple atoms) d.
Describe which coulombic factor is affected by electron shielding (how and why) [electron shielding being the result of core electrons interfering in nuclear attraction for valence electrons] e.
Describe which coulombic factor is affected by nuclear charge (how and why) [nuclear charge is the positive charge of the nucleus…more protons = more nuclear charge…this differs from effective nuclear charge] f.
The formula to the below is Coulomb’s Law. You do not need to memorize this formula, nor will you be given this formula (so no calculations with it), but you do need to be able to describe the variables in the formula and their relationship to F (F= force of attraction and/or repulsion between two charged particles)
3.
Atomic Emission Spectra a.
Describe the process by which atomic emission spectra are produced by electrons b.
Infer relative electron position from nucleus from atomic emission spectra (& be able to explain why one would infer differences in electron position) c.
Determine if a change in energy level (rising or falling) is resulting in energy absorption or release d.
Use Coulombic factors to predict/explain relative magnitude of difference in energy needed to occupy each energy level (ex: is more energy required to move from energy level 1

2 or from level 2

3? ) e.
Calculate change in potential energy for an electron to move between energy levels of an atom if given the formula to find the energy required to occupy a particular energy level f.
Predict effect on energy of a photon / form of light / frequency of the light / wavelength of the light if one of the other variables if increased or decreased g.
Perform calculations for energy of a photon / form of light / frequency of the light / wavelength of the light. Relate to specific type of light if given electromagnetic spectrum h.
Explain the photoelectric effect (photos of light with enough energy are able to remove loosely held electrons from metal atoms) i.
Certain constants and equations will be provided. Consult your copy of the Advanced Placement
Equations and Constants handout (this can also be found on our website)

4.
Photoelectron Spectroscopy a.
Identify an element from a PES (and, of course, be able to discuss what is measured on y and x axes) b.
Determine which type of light—UV/visible or infrared is a better choice to generate PES images & why c.
Make & justify predictions of location/height of peaks d.
Explain how PES graphs supply evidence not all electrons are equidistant from the nucleus, but some groups of electrons are equidistant from the nucleus e.
Interpret an electron configuration from a PES diagram (or a PES diagram from e- config) f.
Supply evidence for filling order of electron sublevels (2s is filled before a 2p, 4s before 3d) g.
Use coulombic factors to explain why groups of electrons within the same atom have different ionization energies h.
Use coulombic factors to explain why corresponding groups of electrons of different atoms have different ionization energies (ex: 1s of K vs 1s of Na) & make predictions regarding E
I1
5.
Electron Organization a.
Interpret electron configurations (long form and abbreviated) b.
Draw orbital diagrams or write electron configurations if given the number of electrons (or told the name of the element or ion) c.
Apply/describe rules of electron organization: Pauli Exclusion Principle, Aufbau, Hund’s d.
Classify an electron organization as paramagnetic or diamagnetic
6.
Periodic Trends a.
Use atomic structure & force of attraction (coulombic factors) between nucleus & electrons to explain ionization energy, successive ionization energy, atomic radius, and electronegativity b.
Interpret these trends from evidence (PES, graphs of ionization energy, atomic radius, electronegativity…ex: could be shown graph of electronegativity for elements 1-20 and have to predict relative electronegativity of element 35) c.
Explain effect on radius when an atom becomes a cation or anion (atom vs cation or atom vs anion) d.
Explain why successive ionization energies constantly increase; recognize within each element’s successive ionization energies there are leaps (large % increase) in electron removals & what this indicates about the grouping of this electron (i.e. the electron was part of a filled sublevel; biggest leaps occur when electron is part of filled p sublevel) e.
Examine electronegativity data and ionization energy to determine the most stable form of electron arrangement; be able to explain how the data provides evidence for this prediction (you are not being asked why a filled p sublevel is stable—just asked why this inference was formed) f.
Predict most likely oxidation number of each group of elements based on what is considered a ‘stable’ electron arrangement g.
Identify secondary patterns in ‘stable’ electron organization if given evidence (ex: PES of oxygen vs nitrogen and sulfur vs phosphorus and examine ionization energy of valence electrons)
To ponder:

Chemical reactions are dictated by the particles attempting to achieve a stable electron arrangement. Atoms / ions will lose electrons, gain electrons, or share electrons to achieve chemical stability. Atoms/ions do not ‘want’ anything—they have no brains, hormones, etc…Their behavior is driven by stability o Which elements on the periodic table are least reactive & why? o How do most metals achieve stability? Which metals can do this more quickly than others & why? o How do most nonmetals achieve stability? Which nonmetals can do this more quickly and why?

Electron affinity is the energy change associated with gaining an electron. Atoms that become more stable from the gain of the electron will show a decrease in energy and atoms which become less stable from gaining the electron will show a positive change in energy. Do you think Fluorine has a positive or a negative electron affinity? What about Lithium? Hydrogen?

Magnesium would achieve stability by losing 2 electrons (why?). Would these electrons still require energy to remove or would magnesium just give them away without charging any energy?