5 Written questions
5 Matching questions
- Energy and power are different words for the same thing.
- The spectra of most galaxies show redshifts. This means that their spectral lines ________.
A) have wavelengths that are longer than normal
B) always are in the red part of the visible spectrum
C) have wavelengths that are shorter than normal
D) have a higher intensity in the red part of the spectrum
- Thermal radiation is defined as
A) radiation produced by a hot object.
B) radiation in the infrared part of the spectrum.
C) radiation that depends only on the emitting object's temperature.
D) radiation in the form of emission lines from an object.
E) radiation that is felt as heat.
- Suppose a photon has a frequency of 300 million hertz (300 megahertz). What is its wavelength?
A) 1 meter
B) 1/300,000 meter
C) 300 million meters
D) A photon's wavelength cannot be determined from its frequency.
- The spectra of most galaxies show redshifts. This means that their spectral lines
A) always are in the red part of the visible spectrum.
B) have wavelengths that are longer than normal.
C) have wavelengths that are shorter than normal.
D) have a higher intensity in the red part of the spectrum.
E) have normal wavelengths, but absorption of light makes them appear red.
- a A) 1 meter
- b C) radiation that depends only on the emitting object's temperature.
- c False
- d A) have wavelengths that are longer than normal
- e B) have wavelengths that are longer than normal.
5 Multiple choice questions
- Lines are wider for faster-rotating objects because parts of the object are rotating toward us and parts are rotating away from us.
- C) The wavelengths of spectral lines in the star's spectrum.
- B) The planet is rotating.
- A) Star X is moving away from us faster than Star Y.
- A) 6,000 joules
5 True/False questions
You are currently emitting electromagnetic waves. → True
We can see each other in the classroom right now because we
A) emit thermal radiation.
B) emit visible light.
C) emit infrared light.
D) reflect visible light.
E) reflect infrared light. → D) reflect visible light.
How many atoms fit across the period at the end of this sentence?
E) more than you could count in a lifetime → A) Electrons orbit the nucleus rather like planets orbiting the Sun.
The most common isotope of oxygen has atomic number 8 and atomic weight 16. Another isotope has two extra neutrons. What are the atomic number and atomic weight of this isotope? → The atomic number would still be 8 because the number of protons wouldn't change, but the atomic weight would increase to 18.
If a material is transparent, then it
A) reflects light well.
B) absorbs light well.
C) transmits light well.
D) scatters light well.
E) emits light well. → B) absorbs most light.