Spectrum

Electron Configuration & Decay

isoelectronic: same electron config (ex: F- & Ne)

Config for anions (move to RIGHT x spaces), cations (move to LEFT x spaces)

*****Transition Metals will lose its valence S electrons before losing and d electrons, so GET RID OF LAST "4S e's" AND PUT THEM IN THE LAST D ORBITAL!!!!!!!!!! (Even though 4s should be lower energy than 3d...TM's more stable with unfilled 4s and quasi-filled 3d orbital, rather than fillied 4s orbital...)

"I dont think there is a hard rule for transition metals which makes it a lot trickier. Some of them have d orbitals that are degenerate with the 4s orbital (same energy level). In some cases, it is better to have all half filled orbitals like 3d5 via Hund's rule. Supposedly this makes it more stable than say 4s2 3d3 and this explains why some orbitals can lose 4s electons before 3d ones even though 4s is lower in energy. Others can be different where the 3d orbital is at a higher energy level than the 4s orbitals."

diamagnetic: all of its e's (even # or all e-'s PAIRED) spin-paired, NO net magnetic field, REPELLED by a magnetic field

paramagnetic: all of its e's (odd-numbered or some e-'s UNPAIRED) are NOT spin-paired, ATTRACTED to a magnetic field

atomic emission spectrum: light emitted when when an atom's electrons FALL to their ground states

atomic absorption spectrum: light absorbed when an atom's electrons are EXCITED to higher energy levels

"Bohr atom" has only 1 electron...so count scenarios properly (Model for the Hydrogen atom)

In balancing ADDITION of alpha particle, balance out equation of mass and atomic numbers with this:

Alpha decay: Reduces the parent’s atomic number by 2 and mass number by 4 (releases an alpha particle = HELIUM atom: 2 protons and 2 neutrons). Any element with atomic number greater than 83 will automatically undergo alpha decay and start releasing protons/neutrons in the form of alpha particles.

http://www.youtube.com/watch?v=TEPVL-3DEtg

- Decreases the number of neutrons AND protons in large nucleus

Beta decay: Neutron decomposes into a Proton (and Electron), or vice versa via weak nuclear force

http://www.youtube.com/watch?v=1j-eDPLSBm0

*Mass number stays the same!!

- β^- à TOO MANY neutrons

o Increases the number of protons

- ex: Carbon 12 vs. Carbon 14... Carbon 14 gains a P+, releases an E-

- β⁺ à TOO FEW neutrons

o Decreases the number of protons

Electron Capture: Converts protons into neutrons

- nucleus draws in inner-shell electron, P and E react to form a Neutron

*Mass number stays the same, only Atomic number changes!! (ex: Rb to Kr)

http://www.youtube.com/watch?v=mhhAXQ5euYw

- Decreases number of protons, porque hay demasiado!

Gamma decay: Simply the expulsion of energy. Does not change the identity of the nucleus. Gamma photons emitted so atom can relax to its ground state.

- Gamma rays are emitted by the nucleus! and are often used in medicine to KILL CELLS

http://www.mcatquestion.com/findquestion.php?arg1=1044

one of like a trillion HALF-LIFE EQUATIONS:

Gradients (all about the SOLUTE)

The plasma membrane of a cell lets water pass freely. Water will flow toward the side that has the most dissolved molecules (called solutes). Said another way, water will flow from a hypotonic solution toward a hypertonic solution until both sides of the membrane reach equilibrium.

a HYPERTONIC solution has more solutes than cell cytosol (H2O flows OUT of cell)

- cytoplasm of the cell has a lower solute concentration than the extracellular medium

a HYPOTONIC solution has less solutes than cell cytosol (H2O flows INTO the cell)

- cytoplasm of the cell has a higher solute concentration than the extracellular medium

- too much inflow, cell my lyse

- “Kaplan Exclusive!”: Look how the O in hypotonic looks like a SWOLLEN cell!

an ISOTONIC solution has the same solute concentration on both sides.

If a cell is in a Hypertonic solution, the cell will shrink.

If a cell is in a Hypotonic solution, the cell will expand.

If the cell is in an Isotonic solution, the cell will remain the same.

If the cell is Hypertonic with respect to the medium, it will expand, this infers that the solution it is in, the medium, is Hypotonic.

If the cell is Hypotonic with respect to the medium, it will contract(shrink), this infers that the solution it is in, the medium, is Hypertonic.

Good student-Doc thread on urine hypertonicity relative to blood: http://forums.studentdoctor.net/archive/index.php/t-833556.html

Stoichiometry trix

Limiting reagent: NOT nec. species in smallest amount, but one that is CONSUMED FIRST

***pay attention to consumption behavior, not initial quantities!

grams₁ à moles à [stoich REAC/PROD] à grams₂

1) BALANCE the equation!!!

2) Do flow chart with ONE of the products--doesn't matter which, just pick one and STICK to it for the sake of comparison!!

3) Less gram #2 value is LR

http://www.chem.tamu.edu/class/majors/tutorialnotefiles/limiting.htm

****calculate number of MOLES (without stoich. numbers) first...

FONClBrISCH (most electroneg to least electroneg)

- sum of oxidation numbers must equal overall charge (indicates what the atom is doing with its valence electrons when it forms a compound)

Electrochemistry

• E^o is a type of energy per electron so it remains unchanged even if we double the numbers of reactants and products in the reaction

• If an equation is reversed (so that the reactants become the products), the sign of E^o is also reversed

• The cell's emf (electromotive force, often referred to as the cell voltage), is calculated by adding together the E^o values for each half reaction:
  E^o_cell = E^o_reduction + E^o_oxidation

• The reaction is spontaneous in the direction as written if
  E^o_cell > 0
  (E^o_cell positive)

• The reaction is spontaneous in the reverse direction to that written if
  E^o_cell < 0
  (E^o_cell negative)

• A galvanic cell (voltaic cell) produces electricity so the overall cell reaction must have a positive E^o_cell value
  (E^o_cell > 0)
• http://www.ausetute.com.au/calcelemf.html

E_cell = E_cathode – E_anode

E_cell must be > than 0 for the reaction to be spontaneous! So by knowing how to subtract what, you know WHICH “half-cell” is the cathode, and which is the anode.

*If both half-reactions appear to be reductions, the OPPOSITE direction of each is oxidation.

Electron movement (wire)

***ELECTRONS ALWAYS MOVE "AWAY" from ANODE, and "COME TO" the CATHODE.

ANODE = site of OXIDATION

CATHODE = site of REDUCTION

ION movement (salt bridge)

ANIONS (-) move to the ANODE

CATIONS (+) move to the CATHODE

***ANODE and CATHODE are just sites/locations in space (ex: California & New York), determined by the movement of IONS...do not confuse!!!

Galvanic (Voltaic) Cell: converts chemical energy of oxidants and reductants into electrical energy Electrodes: are conductors used to permit the flow of electrons in an electrochemical cell. One electrode is the anode, the other is the cathode. Anode: Oxidation occurs at anode Anode is negative Anode disintegrates Cathode:Reduction occurs at cathode Cathode is positive Solid deposits on cathode Salt bridge: allows for migration of ions to complete the electrical circuit Electron Flow: from anode to cathode (e- AWAY from ANODE, COME towards CATHODE)!!! Electrons flow from negative to positive Spontaneous Reaction: E0 for the galvanic cell is positive

Source: http://www.ausetute.com.au/voltcell.html

Electrochemical Cells

Galvanic and Electrolytic Cells

Oxidation-reduction or redox reactions take place in electrochemical cells. There are two types of electrochemical cells. Spontaneous reactions occur in galvanic (voltaic) cells; nonspontaneous reactions occur in electrolytic cells. Both types of cells containelectrodes where the oxidation and reduction reactions occur. Oxidation occurs at the electrode termed the anode and reduction occurs at the electrode called thecathode.

Electrodes & Charge

The anode of an electrolytic cell is positive (cathode is negative), since the anode attracts anions from the solution. However, the anode of a galvanic cell is negatively charged, since the spontaneous oxidation at the anode is the source of the cell's electrons or negative charge. The cathode of a galvanic cell is its positive terminal. In both galvanic and electrolytic cells, oxidation takes place at the anode and electrons flow from the anode to the cathode.

Galvanic or Voltaic Cells

The redox reaction in a galvanic cell is a spontaneous reaction. For this reason, galvanic cells are commonly used as batteries. Galvanic cell reactions supply energy which is used to perform work. The energy is harnessed by situating the oxidation and reduction reactions in separate containers, joined by an apparatus that allows electrons to flow. A common galvanic cell is the Daniell cell, shown below.

Electrolytic Cells

The redox reaction in an electrolytic cell is nonspontaneous. Electrical energy is required to induce the electrolysis reaction. An example of an electrolytic cell is shown below, in which molten NaCl is electrolyzed to form liquid sodium and chlorine gas. The sodium ions migrate toward the cathode, where they are reduced to sodium metal. Similarly, chloride ions migrate to the anode and are oxided to form chlorine gas. This type of cell is used to produce sodium and chlorine. The chlorine gas can be collected surrounding the cell. The sodium metal is less dense than the molten salt and is removed as it floats to the top of the reaction container.

http://chemistry.about.com/library/weekly/aa082003a.htm

Velocity & Acceleration

- If an object is moving with a POSITIVE (sign) for velocity, the (sign of) acceleration will be the way in which the object is behaving

- If an object is moving with a NEGATIVE (sign) for velocity, the (sign of) acceleration will be OPPOSITE to the way in which you'd think the acceleration would be

********If you can't remember this rule of thumb, APPLY THE MATH NUMBERS of change in V over change in T...remember that THIS IS NOT DISPLACEMENT!!!

Trig rules (Quick)