KEY
Earth Science Study Guide
Semester 2 Exam
For the semester exam, you will need to understand the following:
1. Explain all steps of the water cycle, know how to include them in a diagram, and how they
are similar and different:
a. Runoff; surface water
b. Evaporation: liquid to gas
c. Condensation: gas to liquid
d. Precipitation: rain/ snow/sleet/hail
e. Groundwater: fresh water UNDER
ground
f. Infiltration: absorption into soil
g. Transpiration – evaporation from
plants
h. Evapotranspiration- evaporation from
animals, plants, soil
i. What powers the water cycle? SUN
2. Phases of water (what they are and how to
illustrate as a state of matter)
a. Phase changes (How does solid  liquid,
etc)
b. Examples of each phase
3. Properties of water (explain and compare each)
a. Cohesion – surface tension- water sticks to water
b. Adhesion – water sticks to “stuff”
c. Universal Solvent- water (solvent) dissolves “stuff”
(solutes)
d. Which of these contributes MOST to soil
formation? Weathering/ universal solvent
4. Where freshwater/saltwater is found naturally on Earth?
Glaciers – frozen, unacessable; Ocean
5. How to conserve H2O? use less water – examples?
6. What is meteorology? study of the atmosphere and weather
7. Types of thermal (HEAT) energy?
a. Radiation :Sun
b. Convection: circulation (less dense- rise, more
dense- sink) Created by UNEQUAL heating
c. Conduction: Direct contact (touch)
d. How does most thermal energy move in the
atmosphere? Illustrate! Moves through convection
8. Layers of the atmosphere?
a. How are they divided? Changes in
temperature trends:
decrease, increase, decrease, increase
b. Draw the temperature trends graph from
textbook/notes & know how to read it!
c. How many main layers? 4
What happens in each layer with
temperature and pressure?
Temperature varies, pressure
decreases
d. Most dense layer? Troposphere Least dense layer? Thermosphere
e. % and types of gases in the Troposphere? See graph above
9. Greenhouse Gases
a. Identify 4 major gases? 1. Water vapor H20 (Naturally
occuring on Earth) 2. Carbon dioxide CO23. Methane CH4
4. Nitrous oxide NO2 (#2, 3 & 4 affected by humans)
b. Explain what a GG is? Gases that hold on to or absorb
energy ;Responsible for regulating the temperatures in
the troposphere
c. What happens if GG increase? Global temperatures could increase
Decrease? Global temperatures could decrease
10. Meteorology a) Explain. – study of weather and the atmosphere
b) Difference between weather and climate? Weather is the current conditions of a
specific location at a specific time; climate is the average precipitation and temperature
over many years.
c) What are clouds composed of at low altitudes? Liquid droplets High altitudes? Ice
crystals
d) What happens to cold air at the poles? Cold air is more dense so - it sinks
e) What type of weather does an increase in air pressure lead to? Stormy; low pressure
Decrease in air pressure? Fair; high pressure
f) What is barometric pressure? Atmosphere (air) pressure
g) Mountain v Valley weather—compare/contrast. (Think--Mt Charleston v Las Vegas)
Warm
Rises
Cool
Sinks
Valley breeze
Mountain breeze
11. Weather Tools
a. Explain/understand how they work/know what they look like:
i.
Barometer :
ii.
Thermometer : measures the average movement of air molecules
iii.
iv.
v.
Anemometer: Measures wind speed
Wind Sock; Measures wind direction
Psychrometer: measures relative humidity and dew point
(moisture in the air)
vi.
Rain Gauge; measure the amount of precipitation
b. How to use this chart? 1. Measure the dry bulb (air temp) 2. Measure evaporation, the wet
bulb 3. Take the difference between the dry and wet bulb 3. Line up the dry bulb and the
difference. Use like you would a multiplication table.
Dry bulb = 15°F
Wet bulb = 12°F
What’s the answer?
Air
temp
. (F)
0
5
10
15
0
1
2
3
67
73
78
82
33 1
46 20
56 34 13
64 46 29
4
6
12. Weather Maps
a. Know the symbols for following fronts?
i. Cold, Warm, Occluded, Stationary
b. Why weather maps are used/compared daily? To
predict weather; compared to calculate how fast
fronts are moving.
c. How to create a station model?
13. NV Topography
a. Rain Shadow Effect—How does topography create this?
Windward = wet
Leeward = Desert/ dry
b. Type of NV topography? ___Basin_____and____Range______
14. Air Masses
a. What do c & m stand for? M= wet C= dry
b. What do p & t stand for? P = polar t= tropical
c. Where are they found on a map?
d. Which would affect Vegas the most? mP, Mt, Ct
Dry/ Cold
Seasonal
Rainy/ warm
Seasonal
15. Climates
a. Latitude Zones (3 types) Tropical,
Dry/ Cold
Temperate, Polar
i. typical weather in those regions?
ii. know where to find them on a map with latitude given?
b. What does knowing the climate of a region allow a person to do? Plan ahead
16. Seasons
a. What are the four seasons? Northern Hemisphere #1 Winter solstice #2 Vernal
Equinox (spring) #3 Summer Solstice #4 Autumal Equinox (Fall)
b. What causes seasons? Earth’s tilt 23.5o
c. Label and describe the objects & seasons for both the Northern & Southern
Hemispheres on the diagram below. ( Southern Hemisphere is opposite)
Tilt towards
Summer N.H.
Tilt away
Winter S.H.
17. Astronomy
a. Planets—
i.
What are they? Mercury, Venus, Earth, Mars, Jupiter, Saturn , Uranus, Neptune
ii.
How many? 8
iii.
Compare/Contrast each.
INNER PLANET = TERRESTRIAL (ROCKY)
Small diameter
Few moons
No rings
Less gravity
Faster period of revolution
iv.
v.
vi.
vii.
OUTER PLANETS = JOVIAN, GAS GIANTS
Larger diameter
Many moons
All 4 have rings
Strong gravity, More dense
Longer period of revolution
Tilts? What comes as a result? Earth’s tilt( 23.5º causes Seasons
Atmospheres? Venus has very thick CO2
atmosphere = greenhouse effect, that is why it’s
so hot.
Rings/no rings? See compare contrast
Compositions of planets? See compare/ contrast
b. Units for measurement in space?
Which is for largest distances; which is for smaller? Light Year - Distance light can
travel in one year; used in our galaxy and beyond. Astronomical Unit (AU) - Distance
between the Sun and Earth; only used in our solar system.
a. Solar System
i. What objects are included in it? Planets, asteroids, meteoroids, comets
How many stars exist? one, SUN
ii. Where is OUR solar system located within the Galaxy? On one of the outer
arms
b. Galaxies
i. What galaxy are we in? Milky Way
ii. Explain each TYPE of galaxy? (3 types)



Spiral – Milky way, Old stars near center bulge, new stars in arms
Elliptical –mostly old stars
Irregular – when two galaxies collide
iii. Components of a galaxy (disc/bulge/arms/halo/etc)? Where are these?
Disc/ bulge/ halo contain old stars; arms contain newer stars (sun)
iv. How many galaxies are there in the universe? Trillions – limted only by our
ability to count them
v. How many galaxies are there in our solar system? zero
vi. How many stars in a galaxy? trillions
c. Moons
i. What happens to moons as planets get bigger? WHY? More due to the
stronger gravitational pull
ii. Phases of the Moon? Waxing = light on right, moon grows bright
Wanning = light gets smaller on the left
1. Why do they happen? From Earth we only see one side
2. How do eclipses form during the phases? Be able to illustrate.
Solar Eclipse, new moon phase
Lunar Eclipse, full moon
iii. How the Moon formed? By a possible collision when Earth was forming.
iv. Why do we only ALWAYS see one side of the Moon? The rotation and
revolution are the same.
v. Period of Rotation v Revolution
Rotation is spinning on its axis; Revolution is the orbit around something else
- for our solar system - the Sun
d. Other objects in the solar system
i. Comets/Asteroids/ Meteoroids—Know and be able to compare/contrast
each! All orbit the Sun, asteroids (large) and meteoroids (small) are rocky.
Comets are made of rocky icy material with a tail that points away from the
Sun. Very long revolutionary periods
e. Rotation v Revolution: Compare/Contrast the terms (see above)
All Planets revolve counterclockwise around the Sun. All rotate counterclockwise
with the exception of Venus and Uranus. Revolutionary periods increase with
further planets. Outer planets have shorter days than inner planets.