Chapter 2 and 3.2-3.3 Flashcards
What is electromagnetic radiation?
the energy that behaves like a wave and travel at the speed of light in a vacuum, it is LIGHT in a 3D sense
Light traveling includes what
magnetic and electric fields at the same time
What are the 3 characteristics of waves?
wavelengths, frequency. speed
What is the wavelength symbol?
λ (lambda)
What is a wavelength?
distance between 2 peaks in a wave
I—l
/\ /\
What are wavelengths measured in?
meters
What is the symbol for frequency?
v
What is frequency measured in?
1/seconds or just seconds^-1
What is speed measured in?
meters/seconds
What is a frequency?
number of cycles that pass through a point in space, how many cycles there are in a given time frame
What is the speed in terms of waves?
how fast the waves travel
What is the equation for the speed of light?
c = λv
What is the constant for light?
c = 2.998 x 10^8
What is the highest point in a wave called?
amplitude
The relationship between wavelength and frequency is
inversely related
The longer the wavelength, the ___ the frequency
the longer the wavelength, the lower the frequency
The shorter the wavelength, the ____ the frequency
the shorter the wavelength, the higher the frequency
What is the electromagnetic spectrum?
includes gamma rays, x rays, uv light, visible light, infrared, microwaves, radiowaves (FM AM)
What does AM stand for?
amplitude modulation
What does FM stand for?
frequency modulation
What is interference?
how well two waves are able to communicate with one another
What are the two types of interference?
constructive interference and destructive interference
What is constructive interference?
when two waves are parallel to one another and line up to form a wave with higher amplitude ( creates light spots)
What is destructive interference?
when the trough and peak of two waves are touching, forming a straight line and no light
What is diffraction?
occurs when light is scattered from a regular array of points or lines, each color has different angle reflectee
When does diffraction happen?
when light hits a rough surface
What is the ultraviolet catastrophe?
the thought that objects could have an infinite amount of energy when burned
What did Max Plank observe?
energy can be gained or lost only in multiples of hv (h is plank’s constant). energy exists in certain intervals
What is the change in the energy equation?
delta E= nhv
What is the photoelectric effect?
the phenomenon in which electrons are emitted from the surface of a metal (solid) when a specific frequency or higher than that specific frequency of light strikes it
What are the properties of the photoelectric effect?
1) no electrons are emitted by metals below a specified threshold frequency (v0), regardless of light intensity
2) for light with frequencies greater than the threshold, the number of electrons increases linearly with the intensity of light
3) for light frequencies greater than the threshold, kinetic energy from the electrons get emitted
What are photons?
stream of “particles” of electromagnetic radiation, as light intensity increases the more photons there are in the stream
What is the dual nature of light from de Broglie?
all matter exhibits properties of waves and particles
What is de Broglie’s equation?
λ = h / mv (v is velocity)
What is the continuous spectra?
shining white light through a prism, we can see the colors of light
What are the line spectra?
display discrete wavelengths of light in specific quantities
What did Neils Bohr do?
found radii for orbits of electrons and the equation for energy in a hydrogen atom and difference in energy in energy levels
What did the Bohr level suggest?
electrons can only exist in certain energy levels, an electron’s energy is related to the energy level it occupies
IF the electron moves further from the nucleus, what happens?
energy is absorbed
If the electrons move closer to the nucleus, what happens to the energy?
energy is released
What were the drawbacks of the Bohr Model?
only explained electrons in hydrogen, electrons don’t move in orbitals
What are electron density maps?
the more often an electron occupies a point in space, the darker the space becomes
What are quantum numbers?
the ID of an electron
What are the four quantum numbers?
the principal number, the angular momentum number, the magnetic quantum number, and the electron spin quantum number
What does the principal quantum number determine?
how big of an orbital there is and the distance between the nucleus
What is the principal quantum number?
n = #
What does the angular momentum quantum number determine?
shape of the orbital
What is the angular momentum quantum number?
values of 0 to n-1 represented by l letter
l = 0 is what letter?
s
s = which l number?
0