Studied by 4 peoplesolid
definite shape and volume
liquid
definite volume, indefinite shape
gas
neither definite volume or shape, includes plasma
sublimation
solid to gas
deposition
gas to solid
freezing
liquid to solid
melting
solid to liquid
condensation
gas to liquid
vaporization
liquid to gas
intensive property
matter dependent property, independent of material quantity; i.e temperature, density
extensive property
property independent of matter, dependent on quantity of substance; i.e mass, volume, length
physical property
observed/measured without changing a substance into another; easily reversible
chemical property
observed only by reacting a substance to form another
chemical reaction
process in which composition and structure change during a reaction
energy
ability to do work
potential energy
energy stored by position, internal stress, electrical charge, or other factors
kinetic energy
energy of motion
law of conservation of mass
matter is not created nor destroyed in any chemical or physical change
pholgiston
material that escapes when substance is burned
law of definite proportions
a chemical compound contains the same elements in exactly the same proportions by mass regardless of the size of the sample or source of the compound
law of multiple proportions
elements can combine in different ratios to form different compounds
modern view of atom
atoms are unchanged by a chemical reaction, elements are distinguished by the number of protons, can combine in different ways; small nucleus surrounded by electron cloud
molecular formula
shows the types and numbers of atoms combined in a single molecule of a molecular compound
structural formula
indicates the kind, number, arrangement, and bonds but not the unshared pairs of the atoms in a molecule
condensed formula
shows patterns of arrangement, no structural elements
ball and stick model
bonding arrangement showing spatial orientation and size comparison
space filling model
overall shape, more accurate representation
accuracy
closeness of measured value to true value
precision
degree to which repeated measurements show the same result; express variance as a range
captive zero
always significant
leading zero
never significant
trailing zero
significant if decimal point is present
addition/subtraction
least number of decimal places
multiplication/division
least number of sig figs
robert boyle 1661
defined element; elements are not air, earth, water, fire; matter based on observation and demonstration
antoine lavoiser 1774
law of conservation of mass; accurate measurements, matter is neither created nor destroyed
joseph proust 1799
law of definite proportions; pure substances consist of elements in definite/fixed proportions
john dalton 1808
law of multiple proportions; atomic theory; when mass of one element is fixed, masses of other element will be a ratio of whole numbers; elements composed of atoms
hard sphere model
john dalton; indivisible hard spheres with hooks to form molecules
coloumb's law
strength depends on magnitude of charge and distance between two charged particles
cathode ray tube
jj thomson; created stream of particles that can be deflected by magnet, proving negative particles existed. deflection by electric and magnetic field gave charge/mass ratio
millikan oil drop
1909, designed to measure electron charge. x-rays ionize air to transfer electrons onto droplets, magnetic field applied and charge measured based on the balance of gravity and charge
marie curie
positively charged particles, studied uranium, explained that radioactivity is the spontaneous decomposition of atom
wilhelm roentgen
discovered x-rays in 1895
henri becquerel
discovered radioactivity in 1896
alpha particles
positively charged particles with about four times the mass of a hydrogen atom; least penetrative
beta particles
a negatively charged particle (a high speed electron) emitted from the nucleus of an atom during radioactive decay
gamma ray
the high-energy photon emitted by a nucleus during fission and radioactive decay; neutrally charged, highest penetrative ability
plum pudding model
J.J Thomson; model of an atom where electrons were randomly distributed within a positively charged cloud; 1904
ernest rutherford
1909; solar system model of the atom, gold foil experiment; fired negative ions at thin sheet of gold foil, discovered the positively charged atomic nucleus and proposed a nuclear model of the atom in 1911
james chadwick
discovered the neutron in 1932
isotope
atoms of the same element that have different numbers of neutrons
dmitri mendeleev
russian chemist who developed a periodic table of the chemical elements and predicted the discovery of several new elements based on patterns in chemical properties (1834-1907)
columns
groups or families that have similar properties, same number of valence electrons and similar charges
periods
horizontal rows, have same number of electron shells
metals
shiny solids (except mercury), high melting points, high densities, malleable, ductile (drawn into wires), good conductors of heat and electricity, form cations and basic oxides
non metals
dull, brittle, poor conductors of heat and electricity; form anions, ionic compounds, and acidic oxides
metalloids
elements that have properties of both metals and nonmetals; antimony (Sb), germanium (Ge), silicon (Si), arsenic (As), tellurium (Te), polonium (Po), boron (B), and astatine (At)
alkali metals
group 1, always water soluble
alkaline earth metals
group 2, sometimes water soluble, reactivity increases down group
halogens
group 17, diatomic, forms anions, reactivity increases up group, reacts with metals to form metal halides, disinfectants
noble gases
group 18, unreactive, do not easily gain or lose electrons
atomic mass
the average mass of all the isotopes of an element
mass spectrometer
an instrument used to determine the relative masses of atoms by the deflection of their ions on a magnetic field; radius of curve depends on the mass and charge of particles
electromagnetic radiation
proposed in 1800s, described as moving wave of energy with two perpendicular oscillating fields
peak/crest
top of wave
trough
bottom of wave
amplitude
height of crest or depth of trough
wavelength
distance between two corresponding parts of a wave
frequency
the number of complete wavelengths that pass a point in a given time
intensity
amount of energy per second carried through a unit area by a wave; amplitude squared
node
point of zero amplitude on a standing wave
rays in increasing wavelength
gamma rays < x-rays < ultraviolet < visible < infra red < microwave < radio waves
colors in increasing energy
violet > blue > green > yellow > orange > red
1900s physics
light defined by Maxwell's equations, motion defined by Newton's equations; most problems solved and understood
blackbody radiation
the electromagnetic radiation emitted from a heated solid
photoelectric effect
the emission of electrons from a metal when light shines on the metal
ultraviolet catastrophe
classic physics predicted spectrum of emitted blackbody radiation should extend without bound into the ultraviolet, resolved by Plank's hypothesis that the oscillating waves exchange energy in quanta
max plank
1900, light has particle like properties and wavelike characteristics; objects absorb/emit energy in small, specific quantities called quanta into the ultraviolet; related energy absorbed by matter to frequency of light emitted
photoelectric observations
no electrons emitted for low frequency light regardless of intensity; electrons emitted above specific threshold frequency; number of electrons emitted increases with intensity; velocity of ejected electrons increases as frequency increases beyond threshold
albert einstein
1905, concluded light itself is quantized in photons; classical views light as wave, einstein viewed light as particle; light is both
work function
minimum amount of energy to remove one electron, any excess energy is converted to kinetic energy of ejected electron, cannot exceed energy of a single photon of wavelength λ
spectrum
set of wavelengths
continuous spectrum
the emission of a continuous range of frequencies of electromagnetic radiation
fraunhofer lines
1814, a set of dark lines in the otherwise continuous solar spectrum - sunlight is not continuous
bunsen and kirchoff
1859, each element emits unique set of wavelengths
emission
when an electron falls to a lower energy level, a photon is emitted, giving off colors
absorption
absorbed colors are subtracted from continuous spectrum in the appearance of black lines
emission and absorption relationship
a gas absorbs colors when cold that it emits when hot
balmer lines
a series of absorption or emission lines of hydrogen seen at visible wavelengths
bohr model
1913, electrons can only occupy certain stable orbits, "allowed" orbits have quantized angular momentum and quantized energy; electrons can jump between orbits by absorbing or emitting light
n
principal quantum number, designates energy level and orbital size; 1, 2, 3, 4
n = 1
ground state, lowest possible energy level
n > 1
excited state
lyman series
set of spectral lines that appear in the UV region when a hydrogen atom undergoes a transition from energy levels n>1 to n=1
paschen series
set of spectral lines that appear in IR region when electron falls from n>3 down to n=3
energy as n approaches infinity
approaches 0
limitations to bohr model
limited to atom with single electron; doesn't explain WHY angular momentum and energy levels are quantized or why n=1 is lowest energy level
solar sail
einstein says momentum=h/λ; shorter wavelength has higher momentum and light acts like a particle
louis de broglie
moving objects have wave-like behavior; matter shows properties of both wave and particles
Note 
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