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actual yield (isolated yield)
amount of a specified pure product actually obtained from a reaction
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aqueous solution
solution in which solvent is water
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concentration
- amount of solute volume or mass of solution or solvent
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molarity
- moles of soluteL of solution
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percent by mass
- mass of solute X100%
- mass of solution
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percent yield
- actual yield X100%
- theoretical yield
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reaction stoichiometry
qualitative relationship among substances as they participate in chemical reactions
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solute
solvent
solution
- dispersed medium
- dispersing medium
- homogenous mixture of 2 or more substances
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law of conservation of matter
- no detectable change in the quantity of matter during a ordinary chemical reaction
- no loss or gain of matter
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dilution of solutions
V1M1 = V2M2
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absorbtion spectrum
the spectrum associated w/ absorbtion of electromagnetic radiation by atoms resulting from transitions from lower to higher electronic energy states
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alkali metals
alkali earths
halogens
noble gases
- Family: 1A
- Family: 2A
- Family: 7A
- Family: 8A
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alpha paritcle
helium ion w/ a 2+ charge; an assembly of 2 protons and 2 neutrons
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l
- angular momentum quantum number
- designates subshell or set of orbitals w/in a given main shell
- l = n-1
- ex. n=7; l=0,1,2,3,4,5,6
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anode
positive electrode in cathode ray tube
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atomic mass unit (amu)
arbitrary mass unit that is 1/12 the mass of the carbon-12 isotope
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atomic mass (weight)
weighted average of the masses of the constituent isotopes of an element; the relative mass of atoms of different elements
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atomic number
number of protons in the nucleus
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atomic orbital
region or volume in space in which the probability of finding electrons is the highest
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Aufbau ("building up") Principle
guide for predicting the order in which electrons fill subshells and shells in atoms
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Balmer- Rydberg equation
relates wavelengths in the hydrogen emission spectrum to simple intergers
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canal ray
a stream of positively charged paricles (cations) that moves toward the negative electrode in a cathode ray tube; observed to pass through canals (holes) in the negative electrode
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cathode
negative electrod in the cathode ray tube
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cathode ray
beam of electrons going from the negative electrode toward the postive electrode in a cathode-ray tube
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cathode ray tube
a closed glass tube containing a gas under a low pressure w/ electrodes near the ends and a luminescent screen at the end near the positive electrode produces cathode rays when high voltage is applied
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chemical periodicity
the variation in properties of elements w/ their positions in the periodic table
-
continuous spectrum
a spectrum that contains all wave-lengths in a specified region of the electromagnetic spectrum; rainbow
-
d orbitals
- begins in the 3rd shell
- 5 orbitals per shell
- 10 electrons total
- higher energy than s and p in the same shell
-
degenerate orbitals
2 or more orbitals that have the same energy
-
diamagnetism
weak repulsion by a magnetic field; associated w/ all electrons in an atom, molecule, or substance being paired
-
electromagnetic radiation
energy that is propagated by means of electric and magnetic fields that oscillate in directions perpendicular to the direction of travel to the energy
-
electron
- subatomic particle
- mass= .00054858
- charge= -1
-
electron configuration
the specific distribution of electrons in the atomic orbitals of atoms and ions
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electron transition
the transfer of an electron from one energy level to another
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emission spectrum
the spectrum associated w/ emission of electromagnetic radiation by atoms or by other species resulting from electron transitions from higher to lower energy states
-
excited states
any energy state other than the ground state of an atom, ion, or molecule
-
f orbitals
- beginning in the 4th shell
- 7 orbitals per shell
- 14 electrons total
- higher energy than s, p, and d orbitals in the same shell
-
ferromagnetism
- the property that allows a substance to become permanently magnetized when placed in a magnetic field
- exhibited by iron, cobalt, and nickle and some of their alloys
-
frequency (v)
the numer of crests of a wave that pass a given point per unit time
-
fundamental particles
- wubatomis particles of which all matter is composed
- protons, electrons, and neutrons are fundamental particles
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ground state
the lowest energy state or most stable state of an atom, molecule, or ion
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group (family)
the elements in a vertical column of the periodic table
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Heisenberg Uncertainty Principle
it is impossible to determine accurately bothe the momentum and position of an electron simultaneously
-
Hund's Rule
each orbital of a given ubshell is occupied by a single electron before pairing begins
-
isotopes
- 2 or more forms of atoms of the same element w/ diggerent masses
- atoms containing the same # or protons but different #s of neutrons
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line spectrum
an atomic emission or absorption spectrum
-
magnetic quantum # (ml)
- quantum mechanical solution to a wave equation that designates the particular orbital w/in a given subshell (s,p,d,f) in which an electron resides.
- the px, py, and pz orbitals have different magnetic quantum #s
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mass number
the integral sum of the numbers of protons and neutrons in an atomm
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mass spectrometer
an instrument that measures the charge-to-mass ratios of charged particles
-
metal
nonmetal
metalloid
- an element below and to the left of the stepwise division (metalloids) of the periodic table; about 80% of the known elements
- elements above and to the right of the metalloids in the periodic table
- elements w/ properties intermediate between metals and nonmetals: B, Si, Ge, As, Sb, Te, Po, and At.
-
natual radioactivity
spontaneous decomposition of an atom
-
neutron
- subatomic particle
- mass= 1.0087 amu
- charge= 0
-
nucleus
the very small, very dense, positively charged center of an atom containing protons and neutrons, except for 11H
-
nuclide symbol
the symbol for an atom,azE, in which E in the symbol for an element, z is its atomic number and a is its mass number
-
orbital
each allowed wave description of a stable state for an electron in an atom; a region of space in which the probablility of finding an electron is high
-
p orbitals
beginning with the second shell, a set of three degenerate, mutually perpendicular, equal-arm, dumbbell-shaped atomic orbitals per shell
-
pairing of electrons
interaction of two electrons with opposite ms values in the same orbital also known as spin pairing
-
paramagnetism
attraction toward a magnetic field, stronger than diamagnetism, but still very weak compared w/ ferromagnetism; due to presence of unpaired electrons
-
Pauli Exclusion Principle
no 2 electrons in the same atom may have identical sets of 4 quantum numbers
-
period
the elements in a horizontal row of the periodic table
-
periodic law
the properties of hte elements are periodic functions of their atomic numbers
-
periodic table
an arrangement of elements in order of increasing atomic number that also emphasizes periodicity
-
periodicity
regular periodic variations of properties of elements w/ atomic number (and position in the periodic table)
-
photoelectric effect
emission of an electron from the surface of a metal, caused by impinging electromagnetic radiation of certain minimm energy; the resulting current increases with increasing intensity of radiation
-
photon
a "packet" of light or electromagnetic radiation; also called a quantum of light
-
n
- principal quantum number
- designates the main shell, or energy level, in which an electron resides
-
proton
- subatomic particle
- mass= 1.0073
- charge= +1
-
quantum
- a "packet of energy"
- proton
-
quantum mechanics
a mathematical method of treating particles ont he basis of quantum theory, which assumes that energy (of small particles) is not infinitely divisible
-
quantum numbers
numbers that describe the energies of electrons in atoms; they are derived from quantum cechanical treatment
-
s orbital
sperically symmetrical atomis orbital; one per shell
-
spectral line
any of a number of lines corresponding to definite wavelegths in an atomic emission or absorption spectrum; these lines represent the energy difference between two energy levels
-
spectrum
display of component wavelegths of electrommagnetic radiation
-
ms
- spin quantum number
- indicates the relative spins of electrons ("spin up or spin down")
-
wavelength
the distance between two identical points of a wave
-
Rutherford
his "oil-drop" experiment was used to determine the exact electrical charge on an electron and its exact mass
-
Einstein and Planck
proposed that electrons behaved like "little packets of energy" which were called "photons" or "quanta". Einstein is also associated with the "photoelectric effect
-
Bohr
his model of the atom had a very small nucleus at the center surrounded by several circular orbits in which the electrons were placed. his model was used to explain the spectrum of hydrogen and the rydberg equation
-
Heisenberg
Uncertainty principle
-
Pauli
exclusion principle- no 2 electrons in an atom may have identical sets of 4 quantum numbers
-
Rutherford
gold leaf experiment- led to a new model of the atom in which there is a small dense nucleus surrounded by a diffuse electron cloud
-
Thomson
- plum pudding of raisin muffin model
- identified cathode rays as being electrons
-
Hund
hund's principle- orbitals of equal energy are half-filled w/ electrons before spin pairing occurs
-
Mendeleev
father of the periodic table
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de Broglio
concluded that very small particles such as electrons also display wave properties
-
Goldstein
noticed that a beam of positive particles were generated in vacuum tubes in addition to cathode rays. these poitive paritcles wer called "canal rays" and eventually identified as protons
-
Moseley
in 1913, young englishman that determined that the atomic number of an atom was more fundamental to determining the properties of the elements than atomic weight. he enlisted in the british army and was killed at Gallipoli in 1915
-
Sir William Crookes
- first to use cathode ray tubes
- determined that cathode rays are negatively charged and have mass
-
Chadwick
discovered the nucleus of the atom contains more than just protons (neutrons)
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