1. Test question 10.1 • The present-day atmosphere of the Earth formed primarily through: • X Accretion from the solar nebula • V Out-gas from volcanic eruptions • X Evaporation of earth’s ocean • X Bombardment of micro-meteorites.

2. Test question 10.2 • Air are thinner in high mountains than on the sea level because • xOceansare the dominant supplied of air • xAirmolecules have a tendency to cool near the ground • vApressure gradient is established to balance against gravity • xMoleculesescapes into inter-planetary space near the top of atmosphere

3. Test question 10.3 • Temperature on Earth is 300K. If the thermal speed of hydrogen molecule is 3km/s, that of oxygen molecules (with 16 times the mass of hydrogen molecules) would be • v0.75km/s • x1.5 km/s • x3 km/s • x6 km/s

4. Test question 10.4 • Temperature on Mercury is 800K and on Mars is 200K. If the thermal speed of hydrogen gas in Mercury’s primitive atmosphere is 4km/s, that in Mars’ primitive atmosphere would be • x8km/s • x4km/s • v2km/s • x1km/s

5. Test question 10.5 The best evidence for global warming on the Earth today is • xSummers are getting hotter everywhere • xOceanlevel is rising by 1cm each year • vTheCO2 content in the Earth atmosphere is rapidly rising • xThesize of the Sahara desert is expanding

6. Test question 10.6 • Venus atmosphere is much hotter than the Earth atmosphere mostly because • xVenusis closer to the Sun • xVenusdoes not have a moon to block out the Sun light • xVenusdoes not have an ocean to cool its surface • vthelarge carbon dioxide content in Venus atmosphere leads to a strong green house effect

7. Test question 10.7 • The large seasonal sand storm on Mars is caused by • vPressure changes associated with sublimation and condensation of carbon dioxide near Mars poles • xPeriodicrelease of air from volcano on Mars • xEpisodicaccretion of gas at different part of the orbit • xEscapeof hydrogen due to UV radiation from the Sun.

8. Test question 10.8 The surface soil on Mars is red because: • xItis covered with red alge • xItreflects red solar photons much more effectively than blue photons • vWatermolecules have been readily dissociated by solar radiation and the residual oxygen reacts with the soil • xMarsis covered with red hot lava