February 20-27, 2015
ATOMIC
STRUCTURE REVISITED
99% OF ALL CHEMISTRY CAN BE EXPLAINED BY THE ARRANGEMENT OF
THE ELECTRONS IN THE ATOMS, IONS OR MOLECULES
Neils Bohr electrons have energy (E)
The Bohr Atom
a) There is a nucleus (this was
Rutherford's discovery).
b) The electrons move about the nucleus in "orbits" also called
energy levels or shells.
c) When an electron moves from one energy level to another, the energy lost or
gained is done so ONLY in very specific amounts of energy. These specific amounts of energy are called
quanta. The energy is said to be
quantized.
d) Specific spectra (light energy) are
absorbed or released when an electron moves from one energy level to another.
e) Each element absorbs or releases
spectra that are specific for that element and therefore can identify the
element.
MAX PLANCK
MATTER CAN LOSE OR GAIN ENERGY IN SMALL, SPECIFIC AMOUNTS CALLED QUANTA
QUANTUM
THE AMOUNT OF ENERGY NEEDED TO MOVE AN ELECTRON FROM ITS PRESENT ENERGY LEVEL
TO THE NEXT HIGHER ENERGY LEVEL
Eq=hγ
Eq=ENERGY
OF A QUANTUM H= PLANCKS
CONSTANT γ= FREQUENCY
LIGHT
ENERGY THAT TRAVELS IN WAVES.
WAVES
A DISTURBANCE THAT CARRIES ENERGY
ELECTROMAGNETIC RADIATION
waves that travel at the speed of light (3.0 x 1023 m/sec) and can
travel in any medium including a vacuum.
WAVELENGTH
THE HORIZONTAL DISTANCE BETWEEN TWO IDENTICAL POINTS ON TWO ADJACENT WAVES
FREQUENCY
the number of waves that pass by per second. Frequency is usually measured in
Hertz (cycles/sec)
AMPLITUDE
Amplitude is the distance from the
rest position to the crest position which is half the vertical distance from a
trough to a crest
SPECTROSCOPE
INSTRUMENT USED TO MEASURE THE WAVELENGTH OF VISIBLE LIGHT
ELECTRON CONFIGFURATION
THE WAYS IN WHICH THE ELECTRONS ARE ARRANGED AROUND THE NUCLEUS
PHOTON
A QUANTUM OF LIGHT ENERGY
RULES FOR ELECTRON CONFIGURATION
1) AUFBAU PRINCIPLE: ELECTRONS WILL ALWAYS OCCUPY THE LOWEST ENERGY ORBITALS
AVAILABLE.
2) PAULI EXCLUSION PRINCIPLE: A MAXIMUM OF 2 ELECTRONS (WITH OPPOSITE SPINS)
CAN OCCUPY AN ORBITAL.
3) HUND'S RULE: FOR EQUAL ENERGY ORBITALS, ELECTRONS WILL OCCUPY EACH ORBITAL
BEFORE PAIRING UP
NOBEL GAS (SHORTCUT) ELECTRON CONFIGURATION IS DONE BY FIRST WRITING THE
PREVIOUS NOBEL GAS IN PARANTHESES, FOLLOWED BY THE REMAINING ELCTRON
CONFIGURATION.
VALENCE ELECTRONS:
THE ELECTRONS IN AN ATOMS OUTERMOST ORBITALS. VALENCE ELECTRONS DETERMINE THE
ELEMENTS CHEMICAL PROPERTIES.
LIGHT
ENERGY THAT TRAVELS IN WAVES.
ALSO CALLED ELECTROMAGNETIC RADIATION
ELECTROMAGNETIC RADIATION
WAVES THAT DO NOT NEED A MEDIUM TO TRAVEL AND TRAVEL AT THE SPEED OF LIGHT (3.0
X 10^23 METERS PER SECOND) IN A VACUUM.
RADIATION
THE EMISSION OF ENERGY AS ELECTROMAGNETIC WAVES
WAVES
A DISTURBANCE THAT CARRIES ENERGY
WAVELENGTH
THE DISTANCE BETWEEN TWO IDENTICAL POINTS ON TWO ADJACENT WAVES
FREQUENCY
THE NUMBER OF WAVES THAT PASS THROUGH A SPECIFIC AREA PER SECOND
SPECTROSCOPE
INSTRUMENT USED TO MEASURE THE WAVELENGTH OF VISIBLE LIGHT
ELECTROMAGNETIC SPECTRUM
THE RANGE OF ALL POSSIBLE FREQUENCIES OF ELECTROMAGNETIC RADIATION
ENERGY LEVELS
A REGION AROUND THE NUCLEUS OF THE ATOM WHERE THE ELECTRON IS MOVING.
GROUND STATE
THE LOWEST ENERGY LEVEL OCCUPIED BY AN ELECTRON. THE MOST STABLE STATE OF THE
ATOM.
EXCITED STATE
AN ENERGY LEVEL HIGHER THAN THE GROUND STATE
ATOMIC EMISSION
FREQUENCIES OF ELECTROMAGNETIC RADIATION EMITTED DUE TO AN ATOM'S
TRANSITION FROM A HIGHER ENERGY LEVEL TO A LOWER ENERGY LEVEL
february 5-20, 2015
Kinetic molecular theory
The tiny particles (atoms,molecules) in all forms of matter are in constant motion.
The Gas Laws
Boyle's Law
The volume of a fixed amount of gas,at constant temerature, varies inversely with the pressure
P1 x V1 =P2 x V2 = constant
Charles Law
The volume of a fixed amount of gas, at constant pressure, is directly proportional to its Kelvin temperature
V1 = V2 = constant
T1 T2
Gay-Lussac's Law
The pressure of a fixed amount of gas, at constant volume, is directly proportional to the Kelvin temperature
P1 = P2 = constant
T1 T2
Kelvin temperature scale
the temperature scale in which the freezing point of water is 273K and the boiling point is 373K. 0K is absolute zero.
The Combined Gas Law
A single law that states the relationship between pressure, volume and temperature of a fixed amount of gas.
P1 x V1 = P2 x V2
T1 T2
STP (Standard temperature and pressure)
the conditions in which the volume of a gas is often measured; standard temperature is 0 celsius, standard pressure is 1 atm
Daltons Law of Partial Pressure
at
constant volume and temperature, the total pressure of a mixture of
gases is equal to the sum of the partial pressures of all the gases
present.
Ptotal = P1 + P2 + P3 + ....
ideal gas law
the relationship between pressure, temperature, volume and moles
PV=nrt
Effusion
when molecules escape through tiny holes in a container
Graham's Law of Effusion or Diffusion
The rate of effusion or diffusion of a gas is inversely proportional to the square root of its molar mass Avogadro's Principle
equal volumes of gas at the same temperature and pressure contain equal numbers of particles.
Molar Volume
The volume of one mole of gas at STP. Molar volume at STP is 22.4L
February 21, 2013
Honors
The class took the first test of the third marking period.
Theoretical Yield
The amount of product that could form during a chemical reaction. Theoretical yield is calculated from a balanced chemical equation.
Actual Yield
The amount of product that is formed when a reaction is carried out
Percent Yield
The ratio of the actual yield to the theoretical yield expressed as a percentage; a measure of the efficiency of a reaction
Percent Yield = actual yield X 100
theoretical yield
February 19, 2013
Honors
Students finished a stoichiometry lab to start the class
Limiting Reactant
The reactant that is used up first in a chemical reaction. The limiting reactant determines the amount of product that can form.
Excess Reactant
The reactant that is present in a quantity that is more than enough to react with the limiting reactant.
students reviewed for the test on thursday, Feb 21 and worked on the two worksheets you can download below.
limiting_ractant_ws.pdf | |
File Size: | 85 kb |
File Type: |
limiting_reactant_ws_2.pdf | |
File Size: | 122 kb |
File Type: |
February 15, 2013
Honors
Students worked on a stoichiometry lab to start the class
Limiting Reactant
The reactant that is used up first in a chemical reaction. The limiting reactant determines the amount of product that can form.
February 13, 2013
Honors
Hydrate
a compound that has a specific number of water molecules bound to it.
Students worked on a stoichiometry lab
February 11
Honors Chemistry
Students discussed the mole lab we did last week.
We reviewed mole to mole stoichiometry from the last class and worked on a mole to mole worksheet that can be downloaded below.
The teacher then introduced stoichiometry involving mass.
Students then worked on several
mass/mass or mass/mole problems.
Students then worked on a worksheet that involved mass/mass problems.
you can download the mass/mass worksheet below.
We then discussed the next lab.
Hydrate
a compound that has a specific number of water molecules bound to it.
stoichiometry_mass_ws.pdf | |
File Size: | 90 kb |
File Type: |
mole-mole_stochiometry_ws.pdf | |
File Size: | 95 kb |
File Type: |
February 7
Honors Chemistry
Students began class with a lab that tested them on their knowledge of the mole. Each lab group was responsible to hand in a lab report that will count as a lab grade. The lab report can be downloaded below.
moles_moleculesand_grams_lab.pdf | |
File Size: | 118 kb |
File Type: |
Stoichiometry
The quantitative relationship between the amounts of reactants used and products formed in a chemical reaction
Mole Ratio
The ratio between the numbers of moles of any two substances in a balanced chemical equation.
Students worked on the worksheet that can be downloaded below
mole-mole_stochiometry_ws.pdf | |
File Size: | 95 kb |
File Type: |