Chapter 7 Flashcards
what are the 2 classes of objects
matter and electromagnetic radiation
describe the characteristics of matter
-has both volume and mass
-has a defined position in space/time
-follows newton’s law
describe the characteristics of electromagnetic radiation
- doesn’t have mass
- delocalized and propagated through waves
-follows maxwell’s equations
what’s the purpose of electromagnetic radiations
allows energy to travel through space
what are the 3 characteristics of electromagnetic radiation
1) wavelength (lambda): distance between two peaks/bottoms in waves
2) frenquency (mu): amount of waves/cycles per sec that pass at a given point
3) speed (C): speed of light
how are wavelenght and frenquency related
inversly proportional
define waves
continuous repeated change/oscillation through matter or a physical field
define light
a type of electromagnetic wave that contain oscillation through a magnetic field and that travels space
true or false
Energy can only be lost/gained through multiple integers
true
Whats Plank’s equation and its purpose
E=hv
gives us the electronic transiton of an electron
Why is energy considered to be quantized
system can only transfert energy whole quanta/packets
whats the photoelectric effect
when electrons are ejected fro a metal or other materials because light is shining on it.
Fill the blank
Light has both propertie of — and —
wave and matter
what is light’s duality
particle/wave duality
True or false
energy has matter and matter has energy
true
What two equation did De Broglie mix to fin the E of a photon
E=mc^2 and E=hv
what’s a continuous spectrum
a spectrum that emits all wavelengths of light (rainbow)
whats a line spectra
spectrum where only certain colors appear since only specific wavelengths are present
only certain energies are allowed for electrons.
what are the 4 main concepts of the atomic spectrum
1) electrons move from orbit to orbit, but its easier for them to go from an outter shell to inner one
2) the difference/distance between shells is the wavelength
3) energy is lost when electron transition between shells, that energy is carried out by photon which emit light
4) diff wavelength = diff colors
whats a ground state
lowest possible energy level (n=1), the closest to the nucleus and most stable since more attraction
define the energy level postulate
electrons can only be associated to specific energy levels
true of false
energy is absorbed when electrons move from outter shells to inner ones
false, the energy is omitted
for energy to be absorbed the electrons must move from inner to outer levels.
what are the limitations of Bohr’s model
it only works for one elctron systems and doesn’t take in consideration the particle/wave duality of light
what does the quantum mechanical model explain
it explain electrons according to the particle/wave duality
what does shrodinger’s equation gives us
gives us the probability of finding an electron in a specific region of space.
what does the principal quantum number (n) describe and what is its possible values
n= size and energy of shell, the smaller the value= smaller orbit and energy
values are positive integers above 0
what does the angular momentum quantum number (l) describe and what is its possible values
l= distinguishes the different orbital shapes within an orbit
values range form 0 to n-1
values associated to differentes shapes
what does the magnetic quantum number (ml) describe and what is its possible values
distinguishes the different orientation of orbitals
values: depends on values of l
(-l..,0,..l)
what does the spin quantum number (ms) describe and what is its possible values
distinguishes the 2 differentes possible spins of an e-
values: -1/2 or 1/2
define the pauli’s exclusion principle
no two electrons can have the same set of four quantum number and each orbital can hold up to 2 electrons and they must be of opposite spin
whats a polyelectronic atom
atom with more than one electron, they usually follow the spdf order
why do s orbital have lower energy than d or p orbitals
the closer an orbital is to the nucleus the less energy it has as the attraction between the nucleus and the electrons is stronger therefor it penetrates more
define the Aufbau principle
since protons are added pne by one to build up the elements the electrons are added similarly in the orbital, one by one
define Hund’s rule
the lowest energy configuration can only be obtained if we maximize the amount of unpaired electrons in orbitals
where do we find valence electrons
in the outermost shell of the atom
how does the atomic radius change and why
in a family the atomic radius increases as we go down since the number of orbit increases
in a period, as we go towards the right, the radius decreases since the number of proton increase with creates more attraction and therefor more condensed
true or false
the atomic radius is the distance between two nuclei in a diatomic molecule
true
whats the ionization energy and explain the trend across the periodic table
energy needed to remove the outermost electron to create a cation
as we go down a family it decreases and increases as we go towards noble gases
true or false
the first ionization energy is the strongest
false its the weakest
true of false
ionization energy and electron affinity involves atoms in every state
false on gaseous state
define electron affinity
energy needed to add an electron to create an anion thats more stable
What trends describe electron affinity
from left to right, energy becomes more exothermic
exothermic= electron added so energy released
endothermic = electron removed so energy added
whats the difference between paramagnetic substances and diamagnetic substances
P= weakly attracted to a magnetic field since has unpaired electrons
D= not attracted to a magnetic field since has paired electron
why are pair electrons not attracted to a magnetic field
since the paire electrons have opposite spins they cancel eachother and have no charge unlike an un paired electron
whats the wavelength of microwaves and radar
microwaves= 10^-2 m
radar= 10^-1 m
what the wavelength of far infrared
10^-4 m
between what wavelengths is the visible light spectrum
between 350 and 800 nm
whats the wavelength of near infrared
10^-5 m
whats the wavelength of uv
10^-7 and 10^-8 m
whats the wavelength of x rays
between 10^-9 and 10^-11 m
whats the wavength of gamma rays
10^-12 m
state all waves in order of decreasing wavelength
radar-microwaves-far infrared-near infrared- visible- near uv- far uv- x rays- gamma rays
what are the two atoms with an exception in their last orbitals
Cr: 4s^1 3d^5
Cu: 4s^1 3d^10
define ground state
lowest energy configuration possible
more stable
