Chapter 8-11 Flashcards
Define quantum
Absolutely small
define macroscopic
large
quantum particles can be in how many states at one time?
2 states
what is Schrodinger’s cat?
while unknown, something can be in two states
light is what type of radiation?
electromagnetic
True of false: electromagnetic radiation is a wave
true
what is the speed of light?
c=3*10^8 m/s
what is amplitude?
vertical height of a wave
what is wavelength
distance between adjacent crests
define frequency
number of cycles that pass through a stationary point at a given time; cycle per second; units are Hertz or s^-1
frequency of a wave is proportional to what of a wave
speed and energy
frequency is inversely proportional to what of a wave
wavelenth
what color of visible light has the longest wavelength
red (750nm)
name the parts of a wave spectrum in order of increasing wavelength
gamma, x-ray, uv, visible light, infrared light, micro, radio
what is constructive interference of waves
combining and building of two waves
define defraction
wave bending around obstacle
many metals emit what when light shines on them
electrons
define threshold value
minimum value required to eject electrons from surface of metal
Albert Einstein developed what theory
the photoelectric affect and photons
what are photons
packets of light
what is Plank’s constant
h=6.626*10^-34 J… measure of energy
modern electromagnetic theory
light is lumpy; a shower of particles
what is atomic spectroscopy
sutdy of electromagnetic radiation emitted and absorbed by atoms
when an atom absorbs energy, it does what with that energy
re-emits it as light
emission spectrum can be used to identify what
specific elements
what is Bohr known for
dorming model with fixed electron orbit
radiation is emitted or absorbed only when what happens
electrons jump from different orbits
what is the equation for speed of light
frequency x wavelength
what is the equation for energy of light
Plank’s constant x frequency
who proposed wave nature of electrons
Louis De Broglie
true/false: wavelength is proportional to velocity
true
interference is associated with what nature of electrons
wave nature
wave nature and electron nature are what kind of properties
complimentary; the more we know about one the less we now about the other; the more we know of location the less we know of speed
what is the Heisenburg Uncertainty Principle
impossible to know both position and speed of particle accurately
electron beams carry similar but different BLANK as light
diffraction patterns
what is a probabilty distribution map
statistical map that shows where an electron is likely to be found
what is an orbital
a probabilty distribution map
what are the 4 quantum numbers
n, l, ml, ms
what is the principle quantum number and what does it show
n; determines size and energy of orbital; is the shell; infinite number of shells
what is l
angular momentum; determines shape of orbital; letters assigned sdpf
what is ml
magnetic quantum number; orientation of orbital (planes); values between -l and +l
what is ms
spin orientation; only +1/2 or -1/2
how many sublevels in n=2
2 sublevels
how many orbitals of l=2
l=2 is d sublevel, therefore there are 5 orbitals
the energy of a photon is always positive or negative?
positive
wavelength of photon equals
(plank’s constant x speed of light) / energy
probability density
probability (per unit volume) of find e- at point in space
radial distribution function
probability of finding e- within thing spherical shell at a distance of r from nucleus
probability density is at maximum where
nucleus
RDF is what value at nucleus
zero
what is a node
point where wave function is zero
what is the probabilty of finding an electron at a node?
zero
what was Balmer/Rydberg contribution
relating the wavelength of an atome to the energy of the atom
Mendeleev contribution
organized periodic table based on increasing atomic mass and recognized patterns in properties of elements
Mendeleev’s model didn’t explain what
why
what is electron configuraiton
notation that shows paticular orbitals occupied by eletrons in an atom
what is ground state
lowest energy state
what is an orbital diagram
gives information similar to electron configuration but symbolizes eletrons with boxes and arrows
what is Pauli exclusion principle
no 2 electrons can have same 4 QN, they must have different spins, and only 2 electonrs can occupy a given orbital
Coulumbs law
potential energy of 2 charged particles dpeneds on charges and separation
potential energy does what as particles get further apart
increases
for opposite charges, potential energy is what value and does what as particles get closer
energy is negative and gets more negative as particles get closer
what is shielding
repulsion of one electron by the other
what is effective nuclear charge
actualy nuclear charge experience by an elecron; charge of nucleus minus charge of shielding electron
Aufbau principle
electrons fill one orbital at a time starting with the lowest energy available
Hund’s rule
elecrons fill orbitals in a level singly first with parallel spins
orbitals can hold no more than how many electrons
2 electrons
atomic radius periodic pattern
increases down a column, decreases across a row (atoms become more tightly bundled)
removal of electrons in reverse order of filling EXCEPT for what elements
transition elements
what is a paramagnetic atom
atom or ion that has unpaired electrons and is attracted to magnetic field
what is diamagnetic atom
atom or electron which all electrons are paired
losing electrons has what effect on atomic radii
it get smaller
what is ionization energy
energy requird to remove an electron; always positive
ionization energy periodic pattern
increases up a column and to the right; inverse of size
exceptions to ionization energy include what 2 elements
boron and oxygen
core electrons are equal to what elements
noble gases
define electron affinity
energy required to add an electron to nuetral gas atom
how are core electrons found
subtract valence electrons from total number of electrons
electron affinities are generally what value
negative, exothermic
electron affinity trend
becomes more negative across rows
why do chemica bonds form
they lower potential energy between charged particles
which bonds are stronger: ionic or covalent
ionic bonds
octet rule
stable configuration with 8 valence electrons
which bond are generally the shortest and strongest
triple bonds
polarity is based on what
electron density
what is electronegativity
ability of atom to attract electron to itself; results in polarity
electronegativity trend
increases across a row, decreases down a column
what are the 4 most electronegative elements?
fluorine, oxygen, nitrogen, chlorine
higher electronegativity indicates greater what
polarity
what is dipole moment
measure of separation of positive and negative charge in a molecule; shows polarity
how do you know which elements is central in lewis structure
least electronegative element is the center; terminal atoms are most electronegative
what is a resonance structure
a structure that represents a molecule with multiple correct lewis structures
in nature atoms are acutally delocalized or localized
delocalized: spread out with lower energies
define formal charge
fictitious charge assigned to each atom in a lewis structure that helps distinguish among competing lewis structures
according to formal charge rules, the sum of all formal charges in a molecule must equa what
zero
according to formal charge rules, the sum of all formal charges in an ion must equal what
the charge of the ion
true/false: large formal charges for individual ions are better than small charges
false
negative formal charges should reside on which kind of ion
the most electronegative atom
two elements that often form incomplete octets are
Boron and Beryllium
3rd row elements and on often form what
exanded octets
what is bond energy
energy required to break 1 mole of bond in gas statebon
bond energies are endothermic and therefore always what
positive
What type of bonds have the greates bond energy
stable bonds, noble gases
forming bonds is BLANK while breaking bonds is BLANK
exothermic, endothermic
formula for bond energy
bonds broken minus bonds formed
VSEPR Theory states
electron groups repel each other through coulombic forces
what are the five electron geometries
linear, trigonal planar, tetrahedral, trigonal bipyramidal, octahedral
bond angle for linear
180°
bond angle for trigonal planar
120°
tetrahedyl bond angle
~109°
trigonal pyramidal bond angle
90° and 120°
octahedral bond angle
90°
presence of lone pair changes what two things
molecular geometry and bond angle
for any trigonal bipyramidal, place lone pairs in BLANK positions
equatorial
for octahedral, place lone pairs in BLANK positions
axial
what is the pattern for Carboxylic acids
RCO2H
most acids are what kind of acid
oxoacids
in oxoacids, what two elements are bonded together
hydrogen and oxygen
