# Astronomy college course/Why planets lose their atmospheres/Quiz
## AstroAtmosphericLoss_Study

Template:EduV/quizedit
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### AstroAtmosphericLoss_Study-v1s1

1. It is important to distinguish between molecules (collectively) in a gas and one individual molecule. This question is about an individual molecule. For a planet with a given mass, size, and density, which has the greater escape velocity?
    ___ a) all molecules have the same escape velocity
    ___ b) the heavier molecule has the greater escape velocity
    ___ c) all molecules move at the escape velocity
    ___ d) no molecules have escape velocity
    ___ e) the lighter molecule has the greater escape velocity
2. It is important to distinguish between molecules (collectively) in a gas and one individual molecule. This question is about a typical molecule in the gas. For a planet with a given mass, size, and density, which type of gas is more likely to escape?
    ___ a) atoms in a denser gas are more likely to escape
    ___ b) atoms in a colder gas are more likely to escape
    ___ c) all types of gas are equally likely to escape
    ___ d) atoms in a gas with more atomic mass are more likely to escape
    ___ e) atoms in a hotter gas is more likely to escape
3. Which type of gas is likely to have the faster particles?
    ___ a) a cold gas with low mass atoms
    ___ b) a hot gas with low mass atoms
    ___ c) a cold gas with high mass atoms
    ___ d) a hot gas with high mass atoms
    ___ e) all gasses on a given planet have the same speed
4. What is it about the isotopes of Argon-36 and Argon-38 that causes their relative abundance to be so unusual on Mars?
    ___ a) different chemical properties
    ___ b) different half-life
    ___ c) identical abundance
    ___ d) different speed
    ___ e) identical mass
5. In the formula, ${\frac {1}{2}}m_{\mathrm {atom} }v_{\mathrm {escape} }^{2}=G_{\mathrm {Newton} }{\frac {M_{\mathrm {planet} }m_{\mathrm {atom} }}{r_{\mathrm {planet} }}}$, which of the following is FALSE?
    ___ a) the formula can be used to estimate how fast an atom must move before exiting the planet
    ___ b) the formula is valid for all launch angles
    ___ c) the particle is assumed to have been launched vertically
    ___ d) the formula is valid only if the particle is launched from the surface of planet of radius r$_{planet}$
    ___ e) v$_{escape}$ is independent of m$_{atom}$
6. What statement is FALSE about ${\frac {1}{2}}m_{\mathrm {atom} }\langle v_{\mathrm {atom} }^{2}\rangle _{ave}={\frac {1}{2}}k_{\mathrm {B} }T$?
    ___ a) The average speed of a low mass particle is higher than the average speed of a high mass particle
    ___ b) This equation does not involve the size or mass of the planet.
    ___ c) Temperature is measured in Kelvins
    ___ d) Temperature is measured in Centigrades
    ___ e) The kinetic energy is directly proportional to temperature.
7. ${\frac {1}{2}}m_{\mathrm {atom} }\langle v_{\mathrm {atom} }^{2}\rangle _{ave}={\frac {1}{2}}k_{\mathrm {B} }T$, where T is temperature on the Kelvin scale. This formula describes:
    ___ a) The speed of a typical atom, where m is the mass of the planet.
    ___ b) The the speed an atom needs to escape the planet, where m is the mass planet.
    ___ c) The speed an atom needs to orbit the planet, where m is the mass of the atom.
    ___ d) The speed an atom needs to escape the planet, where m is the mass of the atom.
    ___ e) The speed of a typical atom, where m is the mass of the atom.

#### Key to AstroAtmosphericLoss_Study-v1s1

1. It is important to distinguish between molecules (collectively) in a gas and one individual molecule. This question is about an individual molecule. For a planet with a given mass, size, and density, which has the greater escape velocity?
    + a) all molecules have the same escape velocity
    - b) the heavier molecule has the greater escape velocity
    - c) all molecules move at the escape velocity
    - d) no molecules have escape velocity
    - e) the lighter molecule has the greater escape velocity
2. It is important to distinguish between molecules (collectively) in a gas and one individual molecule. This question is about a typical molecule in the gas. For a planet with a given mass, size, and density, which type of gas is more likely to escape?
    - a) atoms in a denser gas are more likely to escape
    - b) atoms in a colder gas are more likely to escape
    - c) all types of gas are equally likely to escape
    - d) atoms in a gas with more atomic mass are more likely to escape
    + e) atoms in a hotter gas is more likely to escape
3. Which type of gas is likely to have the faster particles?
    - a) a cold gas with low mass atoms
    + b) a hot gas with low mass atoms
    - c) a cold gas with high mass atoms
    - d) a hot gas with high mass atoms
    - e) all gasses on a given planet have the same speed
4. What is it about the isotopes of Argon-36 and Argon-38 that causes their relative abundance to be so unusual on Mars?
    - a) different chemical properties
    - b) different half-life
    - c) identical abundance
    + d) different speed
    - e) identical mass
5. In the formula, ${\frac {1}{2}}m_{\mathrm {atom} }v_{\mathrm {escape} }^{2}=G_{\mathrm {Newton} }{\frac {M_{\mathrm {planet} }m_{\mathrm {atom} }}{r_{\mathrm {planet} }}}$, which of the following is FALSE?
    - a) the formula can be used to estimate how fast an atom must move before exiting the planet
    + b) the formula is valid for all launch angles
    - c) the particle is assumed to have been launched vertically
    - d) the formula is valid only if the particle is launched from the surface of planet of radius r$_{planet}$
    - e) v$_{escape}$ is independent of m$_{atom}$
6. What statement is FALSE about ${\frac {1}{2}}m_{\mathrm {atom} }\langle v_{\mathrm {atom} }^{2}\rangle _{ave}={\frac {1}{2}}k_{\mathrm {B} }T$?
    - a) The average speed of a low mass particle is higher than the average speed of a high mass particle
    - b) This equation does not involve the size or mass of the planet.
    - c) Temperature is measured in Kelvins
    + d) Temperature is measured in Centigrades
    - e) The kinetic energy is directly proportional to temperature.
7. ${\frac {1}{2}}m_{\mathrm {atom} }\langle v_{\mathrm {atom} }^{2}\rangle _{ave}={\frac {1}{2}}k_{\mathrm {B} }T$, where T is temperature on the Kelvin scale. This formula describes:
    - a) The speed of a typical atom, where m is the mass of the planet.
    - b) The the speed an atom needs to escape the planet, where m is the mass planet.
    - c) The speed an atom needs to orbit the planet, where m is the mass of the atom.
    - d) The speed an atom needs to escape the planet, where m is the mass of the atom.
    + e) The speed of a typical atom, where m is the mass of the atom.

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   ##### Study guide

    http://en.wikiversity.org/w/index.php?title=Astronomy_college_course/Why_planets_lose_their_atmospheres&oldid=1388258