Choose the best answer to given of the following. Explain your reasoning with one or more complete sentence.
Ionization is the process by which
(a) electrons escape from atoms.
(b) liquid material enters the gas phase.
(c) molecules break apart into individual atoms.

Choose the best answer to given of the following. Explain your reasoning with one or more complete sentence.\ Some nitrogen atoms have seven neutrons and some have eight neutrons; these two forms of nitrogen are
(a) ions of each other.
(b) phases of each other.
(c) isotopes of each other.

Choose the best answer to given of the following. Explain your reasoning with one or more complete sentence.
Compared to an atom as a whole, an atomic nucleus is
(a) very tiny but has most of the mass.
(b) quite large and has most of the mass.
(c) very tiny and has very little mass.

The graph above is a schematic spectrum of the planet Mars; Mars reflects visible sunlight and emits infrared light, refer to the numbered features of the graph and answer the following question.
Which portion(s) of the spectrum represent(s) reflected sunlight?
a. 1 only
b. 2, 3, and 4
c. 3 and 6
d. the entire spectrum

Why do we say that light is an electromagnetic wave? Describe the relationship among wavelength, frequency, and speed for light.

Choose the best answer to given of the following. Explain your reasoning with one or more complete sentence.
Radio waves are
(a) a form of sound.
(b) a form of light.
(c) a type of spectrum.

Choose the best answer to given of the following. Explain your reasoning with one or more complete sentence.
Compared to red light, blue light has higher frequency and
(a) higher energy and shorter wavelength.
(b) higher energy and longer wavelength.
(c) lower energy and shorter wavelength.

Choose the best answer to given of the following. Explain your reasoning with one or more complete sentence.
Why is a sunflower yellow?
(a) It emits yellow light.
(b) It absorbs yellow light.
(c) It reflects yellow light.

Decide whether the statement makes sense (or is clearly true) or does not make sense (or is clearly false). Explain clearly.
Galaxies that show redshifts must be red in color.

Decide whether the statement makes sense (or is clearly true) or does not make sense (or is clearly false). Explain clearly.
Galaxies that show redshifts must be red in color.

Decide whether the statement makes sense (or is clearly true) or does not make sense (or is clearly false). Explain clearly.
If you could view a spectrum of light reflecting off a blue sweatshirt, you’d find the entire rainbow of color (looking the same as a spectrum of white light).

Decide whether the statement makes sense (or is clearly true) or does not make sense (or is clearly false). Explain clearly.
If the Sun’s surface became much hotter (while the Sun’s size remained the same), the Sun would emit more ultraviolet light but less visible light than it currently emits.

Decide whether the statement makes sense (or is clearly true) or does not make sense (or is clearly false). Explain clearly.\ A “white hot” object is hotter than a “red hot” object.

Scaling the Local Group of Galaxies. Both the Milky Way Galaxy and the Andromeda Galaxy (M31) have a diameter of about $100,000$ light-years. The distance between the two galaxies is about $2.5$ million light-years.
a. Using a scale on which 1 centimeter represents 100,000 light-years, draw a sketch showing both galaxies and the distance between them to scale.
b. How does the separation between galaxies compare to the separation between stars?
Based on your answer, discuss the likelihood of galactic collisions in comparison to the likelihood of stellar collisions