Physics Exam 3

What does “quantum” mean?

the smallest discrete amount of something

Which of the following has the lowest frequency?

Infrared light

Interference effects seen when light passes through a narrow opening provides evidence ....

of the wave nature of light - light sometimes behaves as a wave

When an atom undergoes a "quantum jump" into a lower-energy state, the atom

emits a photon.

What carries more energy: a photon of ultraviolet light, or a photon of red light?

The ultraviolet light photon

The difference between the "ground state" and an "excited state" for a hydrogen atom is

They excited state has more energy, and the atom can radiate when it is in an excited state, but not when it is in a ground state.

Which travels faster in a vacuum, visible light or radio waves?

they travel with the same speed

A certain type of atom has only four energy levels, as shown in the diagram. 

The "spectral lines" produced by this element are all visible, except for one ultra-violet line. The quantum jump that produces the UV line is 

state 4 to 1.

The spectrum of the hydrogen atom differs from the spectrum of the helium atom due to

Their different energy levels and the different frequencies of their emitted photons

What is the ONLY difference in electromagnetic waves?

frequency and wavelength

what are the similarities in electromagnetic waves?

All created by a vibrating charged object, they all have the same speed: “c”, the speed of light (300,000 km/s), All can travel through empty space, all carry energy (radiant energy), They can all be “received” by an appropriate detector

Light is a…

wave

what are the different types of electromagnetic waves?

Gamma rays, X-rays, Ultra-violet, inferred, microwaves, and radio

is this order of electromagnetic waves low to high or high to low frequencies?

Gamma rays—>X-rays—>Ultra-violet—>inferred—> microwaves—>and radio

High to low

Which travels faster: visible light or radio waves

Same speed for both

Frequency and wavelength is related to…

color

Is ROY G BIV in order from lower to higher or higher to lower frequency?

Lower to Higher

Brightness is related to…

amplitude

Which color has more energy – green or orange?

Green

What was Einstein awarded the Nobel Prive in Physics for in 1921?

discovery of the law of the photoelectric effect

Discrete vs. continuous

Individual steps- you can’t just be at any height!

No specific places- can be at any height

Light has dual nature meaning it…

Travels as a wave and interacts as a particle

The _______ _______ is caused by the wave nature of light (wave interference)

Overall pattern

The __________ ____ are cause by the particle nature of light

individual dots

What determines how the shape of the face of this woman will ultimately look in the photo?

Interference of light waves, to form the pattern

How do modern camera sensors work?

They detect one photon at a time

Excited atoms put out light when they…

de-excite

QUANTUM THEORY OF MATTER: 1923-1924

Louis de Broglie

suggests if light (a wave) can sometimes act like a particle (a photon), maybe matter (particles) can sometimes have associated waves.

The wavelength is very ____ for normal-sized objects

Small

For small objects the wavelength is ______.

larger

In general, the ______ the mass, the _______ the wavelength

Bigger, Smaller

Is it easier to see wave interference effects if the wavelength is longer or shorter?

Longer

A proton’s mass is about 2000 times more than an electron.

Assuming that a proton and an electron have the same speed, which one has the longer wavelength?

The electron

With light, the wave is an __________ wave

*And the “particle” is the photon – which is a bundle of light energy

electromagnetic

With matter — what are the waves?

The particle is the matter itself – electron, proton, baseball, etc.

In the electron double slit experiment the electron is more likely to hit where the ______ areas are, and the electron is _____ likely to hit where the dark lines are

More, Less

_____________ suggested that the “wave” is a wave of probability: the probability to find the particle somewhere.

In 1926, Max Born

Probability

the likelihood that a particular event or outcome will occur.

What happens when one eave goes through both slits? (both slits open)

Get the interference pattern

What happens when one wave goes through only one slit? (only one slit open)

No interference pattern

what happens when we have a detector set up to see which slit the wave goes through? (Observations can change the result of an experiment)

No interference pattern

Advantage of quantum computer?

do many calculations at the same time