chem hons s1!
saratoga high chem hons final semester 1
Terms
undefined, object
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- interpretation
- judgment about an observation
- atom
- smallest particle of an element that retains properties of that element
- democritus
- coined "atom"
- heterogeneous
- not uniform composition; 2 or more phases
- planck
- scientist who related energy of a wave to its frequency
- limiting reactant
- reactant that runs out (determines amount of product formed)
- decomposition reaction
- 1 thing turns into 2 things
- carbon dating
- determining the age of objects using the ratio of C-12 to C-14
- beta particle
- converts neutrons into protons; increases atomic number by 1; no mass; decreases neutrons by 1
- mixture
- blend of 2 or more substances
- element
- simplest form of matter
- gamma radiation
- usually emitted w/ alpha + beta particles; electromagnetic radiation; no mass, no charge=no change in mass when emitted
- unit cell
- smallest group of particles within a crystal which retains the geometric shape of the crystal
- density of water
- 1g or 1 mL
- vapor pressure
- pressure due to the gas above the liquid
- binary compound
- compound ending in -ide; only has 2 elements in it
- empirical formula
- lower whole number ratio of atoms of the elements in a compound
- lambda
- symbol for wavelength
- negative q value
- heat flowing out of system; heat released; "exothermic"; feels warm
- melting point
- temp at which a solid melts and becomes a liquid
- millikan
- oil drop experiment: determined exact charge of electron; found mass of electron = 1/1840 mass of H atom
- atmospheric pressure
- pressure caused by gas particles in air/atmosphere
- double replacement reaction
- rxn where given 2 compounds, cations trade places
- dalton's atomic theory
- all elements composed of atoms; diff properties of diff elements can be explained by fact that diff atoms are fundamentally diff; each element made from 1 kind of atom; atoms of diff elements combine in whole number ratios to form compounds; chem rxns change how atoms bonded to each other
- barometer
- measures atmospheric air pressure
- mole
- 6.02 x 10^23 representative particles/mole
- heisenberg uncertainty principle
- can't know an object's position and motion at the same time
- electromagnetic radiation
- energy; travels in waves; visible light is a small section of spectrum
- single replacement reaction
- element + compound turns into new compound + element
- 1/2 mv^2
- kinetic energy formula
- chadwick
- discovered neutron
- allotrope
- different molecular forms of the same element in the same physical state
- kinetic energy
- energy of motion
- fission reaction
- the splitting of a nucleus
- amorphous solids
- solids which lack an ordered internal structure (rubber, glass)
- alpha emission
- radiation: cannot penetrate dead skin, paper; can penetrate soft tissue
- E = h x nu
- planck's constant where h = 6.62 x 10^-34
- percent error
- (absolute value of error/accepted value) x 100%
- crystalline solid
- have orderly arrangement of atoms, ions, molecules that make up the solid
- metallic bond
- attraction of valence electron for positively charge metal ion; bond b/t 2 metals
- precision
- how close a set of measurements is to each other
- nu
- symbol for frequency
- isotope
- atoms with differing numbers of neutrons; differing masses
- 3.0 x 10^8 m/s
- speed of light = c = speed of electromagnetic radiation in a vacuum
- pressure
- force/area
- specific gravity
- compares density of substance to density of a reference substance
- golstein
- discovered proton
- standard temperature and pressure
- STP
- molecular compound
- electrons shared; 2 non-metals; low melting/boiling points; liquid or gas at room temp
- observation
- observe with senses
- perspiration
- sweating
- thermoequilibrium
- heat stops moving; heat moves from hot to cold until the temps are equal
- molar mass
- the mass of one mole of any substance; atomic mass in grams
- transmutation
- the conversion of one element into another
- aufbau principle
- electron enters orbitals with lower energy first
- hess' law
- if 2 or more chemical rxns combine to give a final equation then you can add the deltaH values to get the final deltaH
- jj thomson
- discovered electron; cathode ray tube; plum pudding model
- chemical reaction
- change from reactants to products; rearrangement of bonds between atoms
- critical point
- liquid and gas indistinguishable (super critical fluid)
- law of conservation of energy
- energy cannot be created nor destroyed
- combination reaction
- 2 things combine to form 1 thing
- schrodinger
- wrote mathematical equation for location of electron; based on probability
- half-life
- amount of time it takes for half the atoms of a radioactive isotope to decay to products
- gas pressure
- the force exerted by gas particles (in motion) hitting a body
- mosely
- arranged elements by atomic number
- Calorie
- amount of energy required to raise 1g water 1degree Celcius
- density
- mass/volume
- transuranium elements
- elements with atomic numbers greater than 92; manmade; radioactive
- heat
- energy that is transferred from one substance to another due to temperature differences; can't measure it directly (only its effects)
- combustion reaction
- rxn that involves burning something in oxygen
- representative unit
- formula unit (like a "molecule)
- number of molecules; number of moles
- what coefficients in chem rxns represent
- elastic collision
- energy is transferred totally from one particle to another
- positron
- converts protons into neutrons; decreases atomic number by 1; no mass; increases number of neutrons by 1
- rutherford
- discovered nucleus; bombarded gold foil with pos alpha particles
- molecular formula
- "real" formula; same as or some whole number multiple of the empirical formula
- absolute zero
- 0 K, or -273 degrees celcius; all molecular motion stops
- vacuum
- no particles (air) --> no force --> no pressure
- thermochemistry
- the study of heat changes that occur during a reaction
- percent mass
- (mass of element in compound/molar mass of compound) x 100%
- OKAY!
- KNOW HOW TO CALCULATE EMPIRICAL/MOLECULAR FORMULA. OKAY?!
- excess reactant
- the reactant that is left over
- boiling point
- when vapor pressure = atmospheric pressure
- 760 mm Hg; 101.3 kPa
- 1 atmosphere
- amplitude
- brightness
- photon
- light quanta
- gamma emission
- radiation: can be stopped by several inches of Pb or concrete
- lambda = h/mv
- debroglie equation
- compound
- 2 or more elements chemically combined that can only be separated with a chemical reaction
- photoelectric effect
- shine light on metal to observe effects
- periodic law
- certain properties of elements repeat periodically when arranged by atomic number
- law of conservation of mass
- matter cannot be created nor destroyed (it can be rearranged to form new bonds)
- energy
- the capacity to do work or the ability to supply heat
- triple point
- where all three phases coexist
- hund's rule
- electrons going into orbitals w/ same energy fill one electron per orbital all with same spins
- polyatomic ions
- tightly bound groups of atoms that behave as a unit and carry a charge
- homogeneous mixture
- uniform composition; same throughout; "one phase"
- positive q value
- heat flows into system; heat is absorbed; "endothermic"; takes in heat; feels cold
- isoelectronic
- having the same electron configuration
- percent yield
- (actual yield/theoretical yield) x 100%
- specific heat x mass of a substance
- equation for heat capacity
- pauli exclusion principle
- orbitals may hold at most two electrons; must have opposite spins
- neils bohr
- planetary model: electrons move in fixed paths aroun nucleus, have fixed energy
- 1
- mass of proton; mass of neutron
- hydrocarbon
- CHO
- energy levels
- areas around nucleus where electrons most likely to be found
- Q = CMAT
- Q=CMAT
- alloy
- mixture of 2 or more elements, one of which is a metal
- kinetic theory
- theory: particles in all states of matter are in constant motion
- (% abundance) x (mass of 1 isotope) + (% abundance) x (mass of 1 isotope)
- average atomic mass
- dmitri mendeleev
- developed periodic table (arranged elements by mass, similar properties)
- heat capacity
- amount of energy (heat) required to raise temp of a specific OBJECT
- accuracy
- how close a measurement is to the "true" value
- beta emission
- radiation: can be stopped by wood/aluminum foil
- error
- accepted value - experimental value
- ionic compound
- electrostatic attraction; metal + nonmetal; high melting/boiling points; crystalline solids at room temp
- shielding effect
- electrons closer to nucleus shield outer electrons from nuclear pull
- alpha particle
- helium particle; decreases atomic number by 2, mass by 4, neutrons by 2
- 22.4 L
- 1 mole of any gas at STP
- potential energy
- stored energy (chemical energy)
- frequency
- color
- evaporation
- a cooling process; molecules at a higher temperature leave to become gas, cooler particles left over
- specific heat
- amount of energy required to raise 1g of a SUBSTANCE 1 degree celcius