Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
105 Cards in this Set
- Front
- Back
Scientists realized that the Rutherford model did not explain:
|
where the electrons were located in the space around the nucleus
|
|
first the Bohr model and then the Quantum Mechanical Model evolved as scientists studied the __________ and ________ of light by matter
|
absorption and emission
|
|
taking in of light by matter
|
absorption
|
|
giving off of light by matter
|
emission
|
|
the studies showed that there is an intimate relationship between _____ and an atom's electrons
|
light
|
|
the studies also showed that light behaves as both _____ and _________
|
waves and particles
|
|
Rhythmic disturbances that carry energy through matter or space
|
Wave
|
|
waves in which the medium moves at right angles to the direction the wave travels
|
Transverse Waves
|
|
Transverse waves do not always need a ______ to carry energy
|
medium
|
|
any material through which a wave can transfer energy
|
medium
|
|
water waves transfer energy through _____
|
water
|
|
Earthquakes transfer energy through _____
|
earth
|
|
light waves are transverse waves that need no ______ to transfer energy
|
medium
|
|
top of a wave
|
Crest
|
|
bottom of a wave
|
Trough
|
|
distance from crest to crest or trough to trough on a wave
|
wavelength (λ)
|
|
distance from crest or trough to the rest position of the medium
|
amplitude
|
|
the # of waves that pass a given point in a second
|
frequency (ν)
|
|
The units for frequency are the _____(Hz), cycles/second(cycles/s) or /second ( /s)
|
Hertz
|
|
speed a wave is travelling
|
wave velocity
|
|
transverse waves produced by the motion of electrically charged particles that travel through space at the speed of light—3.00 x 108m/s
|
Electromagnetic Waves
|
|
Electromagnetic waves are also called _____, _________, _______ ______, _______________ _________ because the waves radiate from the electrically charged particles
|
light, radiation, radiant energy, electromagnetic radiation
|
|
all forms of electromagnetic radiation move at a constant speed of about 3.00 x 10^8m/s through a ______ and slightly slower through ______
|
vacuum; matter
|
|
Since air is mostly space, the value of 3.00 x 10^8m/s is light's approximate speed through ___
|
air
|
|
Light wave velocity can be described by the formula:
|
C = λ ν
|
|
the speed of light, 3.00 x 108m/s
|
C
|
|
the wavelength of the wave in meters
|
λ
|
|
the frequency of the wave
|
ν
|
|
this represents an _______ __________ because if λ goes down, ν goes up and if λ goes up, ν goes down
|
inverse proportion
|
|
Together, all forms of EMR form the _______________ ________
|
electromagnetic spectrum
|
|
The greater the frequency or energy, the greater the ______
|
danger
|
|
The greater the _________, the smaller the __________
|
frequency; wavelength
|
|
radio waves have lowest _________, greatest __________
|
frequency; wavelength
|
|
Radio Waves are used in ____________
|
communications
|
|
used in cooking and communications
|
microwaves
|
|
Microwaves carry energy inside food to make the molecules move ______, heating the food
|
faster
|
|
this is the heat given off by everything on earth, living or not. Used in night vision, many devices such as t v remote controls and organisms such as pit vipers use it to find their prey
|
infrared
|
|
ROY G BIV is a small part of EMR
|
visible light
|
|
- harmful to skin if too much exposure
- helpful—used to treat skin disease, sterilize milk & water |
ultraviolet rays
|
|
- used to see inside the body
- go through most muscle but are absorbed by bone |
X-rays
|
|
- highest frequency, shortest wavelength
- most destructive yet some frequencies are used to treat cancer |
Gamma rays
|
|
In the early 1900's, scientists conducted 2 experiments involving the interactions between light & matter that could not be explained by the ____ ______ __ _____
|
wave theory of light
|
|
___ ______ proposed that hot matter does not emit EMR continuously as would be expected if the light given off were in the form of waves
|
Max Planck
|
|
Instead Plank suggested that the light is given off in small, specific amounts called _____
|
quanta
|
|
_______ is the minimum amount of energy that can be lost or gained by an atom.
|
Quantum
|
|
In student terms, a quantum is a "______ __ ______"
|
packet of energy
|
|
the emission of electrons from a metal when light of a certain frequency shines on it
|
Photoelectric Effect
|
|
Electricity is a flow of _________
|
electrons
|
|
Mystery involved is why it took a certain ________ to work
|
frequency
|
|
If the light striking the metal had enough energy, then the _________ were knocked off
|
electrons
|
|
If the light striking the metal did not have enough ______ then the electrons were not emitted no matter how long the light shone on the metal
|
energy
|
|
It seemed that if light were in waves then any _________ would work to emit the electrons
|
frequency
|
|
Photoelectric effect explained by ______ ________
|
Albert Einstein
|
|
The photoelectric effect was expanded on Planck's theory of the _______
|
quantum
|
|
Said that EMR has a duel ____-________ ______
|
wave-particle nature
|
|
While light has wave-like properties, it can also be thought of as a ______ __ _________
|
stream of particles
|
|
Each particle of light carries a _______ __ ______
|
quantum of energy
|
|
Einstein called the particles _______
|
photons
|
|
a particle of EMR having zero mass and carrying a quantum of energy
|
Photons
|
|
the energy in a particular photon depends on the frequency of the _________
|
radiation
|
|
radio waves have lower frequency than gamma rays so a photon from a radio wave has less ______ than one from a gamma ray
|
energy
|
|
The _________ in atoms absorb energy from EMR
|
electrons
|
|
This increases the energy in the atom's electrons by a certain ______
|
amount
|
|
the relationship between the energy in a photon and the frequency of the radiation is represented by the formula:
|
E = hν
|
|
Amount of energy in the photon expressed in Joules
|
E
|
|
Planck’s Constant or 6.63 x 10^-34 Joules / seconds
|
h
|
|
stays the same
|
constant
|
|
Joules is a SI unit for ______
|
energy
|
|
frequency
|
v
|
|
this represents a ______ __________
|
direct proportion
|
|
If _ goes up, then _ goes up
|
E; v
|
|
If _ goes down, then _ goes down
|
E; v
|
|
the electrons in atoms ______ energy
|
absorb
|
|
Einstein said EMR is absorbed by matter only in:
|
whole numbers of photons
|
|
In order for an electron to be ejected from a metal’s surface, the electron must be struck by a single photon with the minimum energy needed to knock the electron loose. This minimum energy corresponds to a minimum frequency. If the photon's frequency is below the minimum, then the electron stays attached to the metal. Since electrons in different metals are bound more or less tightly, different metals require different frequencies to show the photoelectric effect
|
note
|
|
lowest energy state of an atom
|
ground state
|
|
the ground state is the most ______ state of an atom
|
stable
|
|
In the ground state, electrons occupy the ______ ______ ______ possible and carry the least amount of energy to stay in those levels
|
lowest energy levels
|
|
a state in which an atom has a higher energy state than it has in the ground state
|
excited state
|
|
In the excited state, electrons have ________ energy
|
absorbed
|
|
if electrons gain the right amount of energy, they jump to a ______ _____
|
energy level
|
|
When electrons absorb energy and move to higher Energy levels, the atom becomes ________
|
unstable
|
|
The atom returns to the ground state as the electrons give off the same amount of energy that they absorbed in the form of light (photons)
|
electron transition
|
|
Electrons can change energy levels only with _____ amounts of energy. If it only gains some of the energy it just spins faster and won't change ______ ______
|
exact; energy levels
|
|
Examples of electron transition in everyday include:
|
- light bulbs
- fireworks - neon lights |
|
pattern of EMR
|
Spectra
|
|
tool used to the study the structure of atoms and the composition of matter
|
spectroscope
|
|
A spectroscope uses ______ to separate light into a spectrum which can be examined
|
prisms
|
|
A spectroscope bends light different amounts according to its __________
|
wavelength
|
|
There are different types of spectra:
|
- continuous spectrum
- discontinuous spectrum |
|
one color blends into the next because all frequencies of light within the range are being emitted
|
continuous spectrum
|
|
Each element has its own ____ _________ ________ that is like the element's finger prints
|
line emission spectrum
|
|
formed when excited atoms of an element are formed by passing electricity through its gas or vapor under ___ ________
|
low pressure
|
|
the color characteristic of the element is emitted as the electrons return to the ______ _____
|
ground state
|
|
Passing the color emitted by the element through a spectroscope produces the ____ _________ ________ for the element
|
line emission spectrum
|
|
We see narrow bands of color that correspond to the wavelengths of visible light given off by the element as it undergoes ________ __________
|
electron transition
|
|
There are also bands of _____ between the visible colors. These bands represent areas where no light is being emitted. Bands in the ___________ and ________ ranges are sometimes detected but not seen because they are not in the visible range
|
black; ultraviolet and infrared
|
|
Scientists studied the line emission spectrum for hydrogen first. As they tried to explain why not all colors were visible, they devised the _______ _________ _____ of the atom
|
quantum mechanical model
|
|
Bohr linked the atom's ________ with ______ _________
|
electron; photon emission
|
|
electrons circle in ______
|
orbits
|
|
electrons closest to the _______ have least amount of energy
|
nucleus
|
|
the farther the electron is from the nucleus, the _______ energy it has
|
greater
|
|
If an electron gains the right amount of energy, it can move to a ______ ______ _____
|
higher energy level
|
|
The electron has to gain the amount of energy equal to the difference between the higher-energy orbit and the initial lower-energy orbit. Based on the wavelengths of hydrogen's line emission spectrum, Bohr calculated the energies the electrons would have in the various energy levels.
|
note
|
|
It was soon realized that Bohr's model didn't explain the ____ _________ ______ for atoms with more than one electron and did not explain how chemical reactions occur
|
line emission spectra
|