General Astronomy Quiz 5 Flashcards
What is light?
A wave phenomenon
What is sound?
A wave phenomenon
Which of these statements is true?
1) Light and sound can both travel through empty space.
2) Only light can travel through empty space.
3) Only sound can travel through empty space.
4) Neither light nor sound can travel through empty space.
2) Only light can travel through empty space
Do both waves carry energy from one location to another?
Yes
What do sound waves require?
For particles in the air to be compressed parallel to the direction of movement
What do light waves create?
Disturbances that are perpendicular to the motion
What is another term for light?
Electromagnetic radiation/transmission of electromagnetic energy
What is a wavelength?
A measure of the distance between line points on a wave
measured in meters
What is a frequency?
the number of waves passing a point in one second
measured in Hertz
What is the equation for speed?
f * λ (frequency * wavelength)
For EM radiation, is the speed that light waves travel the same for all forms of light?
Yes
What is it called when the speed that light waves travel is the same for all forms of light?
The speed of light
given the “c” and c = f * λ
What is the speed of light?
th physical speed when light waves pass through a vacuum
all forms of light travel at speed “c” in space
What did Einstein win the Nobel prize for?
His work on the photoelectric effect
Can light act as a wave and a particle?
Yes
What happens when light interacts with light?
It acts like a wave
What happens when light interacts with matter?
It acts like a particle
What is a particle of light called?
Photon
Do photons have mass?
No
Do photons move at the speed of light?
Yes, they are light
What do high frequency waves have?
Short wavelengths and high energy (gamma rays, Ultraviolet light)
What is the electromagnetic spectrum?
The range of all possible wave frequencies and wavelengths
Which of the following is NOT a form of light?
1) Radio waves
2) Microwaves
3) X-rays
4) All of the above are forms of light
5) None of the above is a form of light
4) All of the above are forms of light
Since there are only a few forms of light that make it through Earth’s atmosphere, which are they?
-Visible Light
-FM Radio waves
-TV
Which are the types of light that we have discussed…
● has the least energy?
● has the shortest wavelength?
● has the lowest frequency?
● travels the slowest?
● has the least energy? - radio waves
● has the shortest wavelength? - x-rays
● has the lowest frequency? - radio waves
● travels the slowest? - none
Which of the following would be true about comparing X-
rays and radio waves?
1) Radio waves have greater energy and shorter wavelength than X-rays.
2) Radio waves have higher frequency and travel the same speed as X-rays.
3) Radio waves have lower frequency and would travel faster than X-rays.
4) Radio waves have less energy and would travel slower than X-rays.
5) Radio waves have longer wavelength and travel the same speed as X-rays
5) Radio waves have longer wavelength and travel the same speed as X-rays
What did Newton’s ideas of light being a particle come from?
Using a prism
What are spectral curves?
Known as blackbody curves, tells us about a star’s temp
What are spectral lines?
Absorption lines or emission lines, the dips in the curves, or the dark lines that appear in the rainbows
What is heat?
A form of energy associated with the motion of the atoms that make an object
What is temperature?
The average speed of atoms in an object or gas.
motion is due to heat energy
What is absolute zero?
The temperature at which there is no heat energy, all motion stops
What is Fahrenheit?
Not used in science
-water freezes at 32F
-boils at 212F
What is Celsius (Centigrade)?
Standard metric scale
-Water freezes 0C
-Boils at 100C
What is Kelvin (Absolute Scale)?
-Water freezes at 273K
Boils at 373K
What is the temperature of absolute zero?
Absolute Kelvin
between -273 C and -460 F
Do astronomers use the Kelvin scale?
Yes
What is blackbody radiation?
The glow from dense objects with temperatures above absolute zero creating EM
What color is produced when a star has a high temp?
Blue
If a star has a temperature of 6000K, what does the color look like?
Yellowish-white
If a star has a low temp, what color is produced?
Red
What is the temperature of the Sun?
5800K
A piece of metal is heated to a high temperature. Another
piece of metal that is twice as large is heated to a lower
temperature. Which appears redder?
1) The cooler piece of metal appears redder.
2) The hotter piece of metal appears redder.
3) Both pieces look the same color.
4) Cannot tell which piece looks redder.
1) The cooler piece of metal appears redder.
What is a blackbody curve considered?
A continuous spectrum
What is a continuous spectrum?
Hot, high density energy source, rainbow of colors with no gaps
What is an emission spectrum?
Hot, low density gas cloud, a few bright lines on a dark background
What is an absorption spectrum?
Hot, high density and Cool, low density gas cloud, rainbow with some dark lines missing
What does blackbody radiation peak at?
The wavelength based on the temperature of the star
Which is produced by the
Sun?
1) Continuous spectrum
2) “bright line” Emission
spectrum
3) “dark line” Absorption
spectrum
3) “dark line” Absorption
spectrum
What happens to light as it travels through the low density outer layers of a star?
It becomes an absorption spectrum based on the atoms that are there
What is a nucleus?
Massive central part of having a positive electric charge, contains the neutrons for stability
What are protons?
Positively charged particles
What are neutrons?
Like protons, but no electric charge
What is an Electron Cloud?
Electrons in “orbit” about the nucleus
What are atoms?
The smallest possible sample of a chemical element
What does the number of protons determine in an atom’s nucleus?
The atom’s chemical element
What are isotopes?
Two atoms with the same number of protons but different number or neutrons
What is an ion?
When electrons are removed or added to a nucleus
What is a positive ion?
An atom with too few electrons
What is a negative ion?
An atom with too many electrons
What is the Bohr model?
an atom as a small, positively charged nucleus surrounded by electrons orbiting in fixed, circular paths called shells
How do electrons change energy levels?
By absorbing or emitting photons
When a photon is absorbed, it jumps __.
Up
When an electron jumps down, a photon is ___.
Emitted
What is an excited atom?
An atom with an electron in an upper energy level
Where do electrons always stay?
In a ground state
Energy is released from atoms in the form of light when
electrons
1) move in their orbit around the nucleus.
2) are emitted by the atom.
3) are absorbed by atoms.
4) move from low energy levels to high energy levels.
5) move from high energy levels to low energy levels.
5) move from high energy levels to low energy levels.
What is the Doppler Effect?
The shift in the frequency and wavelength of a wave due to relative motion
What terms do we use for the DE?
Redshift and blueshift
