absorption	155
analyzing	165, 166, 147, 148
area	22, 85
Aristotle	81
asteroid	160
atmospheres	159, 160
atoms	149, 150, 151
axis	161
buoyant forces	152
centimeter	160
change	160
characteristics	154, 165, 163
chemical(s)	149, 154, 155, 160, 164, 169
chemical changes	155
chemical reactions	154
circulates	160
climate	160
clouds	160
comet(s)	160
common themes	45
compare	164, 165
components	164
composition(s)	159, 160
compounds	149, 154
conclusion(s)	171, 147
condensation(condensing)	159, 160
continents	160
convection	159
cooling	155
cornea	107
core	159
cosmologist
crust	159, 160
data	143, 144, 145, 146, 147, 148, 150, 159, 164, 171
day	160, 161, 171
decomposition	160
density	150, 152, 153, 154
deposition	160
describe	145, 147, 148, 164
design	143, 145, 147, 161, 165, 162, 163, 164, 166
direction	154, 145
dissolving	160
distances	166
earth	155, 158, 159, 160, 168
earthquakes	159, 160, 168, 169
earth's surface	155-159, 160, 161
eclipses	160
electric current	154
electrical circuits	155, 165
electrical energy	155
electricity	154, 155
elements	149, 154
elevation	160
energy	154, 155, 159, 160, 161, 168
energy of motion	154
energy transmission	155
emission	155
environment(s)	160, 166, 167, 168, 169
erosion	160
experimental procedures	145-148, 164, 171
experimental studies	171
explain	143, 144, 145, 147, 148, 166, 171
evaporation	159, 160
evidence	143, 144, 145, 148, 160, 170
eye	155
features	159
forces	149, 154, 159, 160, 161, 162
fossils	160
friction	149, 154, 166
gases	160
geological	160
geological history	160
graduated cylinders	151
graphs	147, 154
gravity	159, 161, 162
heat	154, 155, 160
inertia	154
information	164
infrared light	155
instructions	159
investigation(s)	143, 145, 148, 151, 159, 161, 165, 166, 170
knowledge	162
laboratory	154
land	159, 160
landforms	160
length	146, 147
life forms	159, 160
light	154, 155, 159
liquids	150, 151, 153
lithosphere	159
magnetism	154
magnitude	154
mantle	159, 160
mass	154
mathematics	145, 146, 148, 170, 171
matter	150, 155
measure	144, 145, 146, 147, 154, 165, 162
measurement devices	165
mechanical energy	155
melting temperature	149
metallic	159
mid-ocean ridges	159
minerals	160
mixtures	154, 160
models	145, 148, 159, 165, 163, 171
molecules	149
moon phases	159, 160
moon(s)	159, 160
motion(s)	145, 147, 149, 154, 160, 161, 162
mountain range (mountain chain)	160
mountains	160
nitrogen	160
nuclear energy	155
object	149, 154, 155, 165, 166
observation(s)	143-145, 148-150, 152, 159, 165, 166, 171
ocean floor	159, 160
oceanic	159, 160
oceans	159, 160, 161, 167
orbit	159, 160, 161
oxygen	160
past (life forms)	160
phases (of the moon)	159, 160
phenomenon(a)	143, 145, 147, 148, 153, 160, 161, 166, 171
physical	146, 166, 167
physical weathering	160
planets	159, 160, 161
plates	160
problem(s)	161-166, 168, 169 
procedure(s)	144, 145, 148, 164
product(s)	161, 164-167, 169
properties	150-155, 159, 160, 166
purpose	165
qualitatively	149
questions	143, 145, 148, 162, 166, 169, 171
reflect (reflected, reflection)	155, 162, 164
refract (refraction)	155
research	167, 171
rock layers	160
rock(s)	160
rotation	161
safety	165-168
satellites	159
scattering (light)	155
science	144, 145, 161, 162, 165, 166, 167, 169, 170, 171
scientific concepts	145, 161, 164
scientific ideas	145, 161, 171
scientific information	143, 145
scientific inquiry	143-145, 148, 161, 166, 170, 171
scientific knowledge	170
scientists	148, 166, 169-171
seafloor spreading	159, 160
seasons	160, 161
sediments	160
soil	160, 168, 169
solar system	159-161, 215-217
solid(s)	160, 161
solutions	165, 166
solve	163, 164
sound	154, 155
speed	145, 154, 166
star(s)	160
sun	155, 160, 161
surface features	160, 161
system-subsystems	145, 155, 160, 161, 165, 166, 169
technological systems	161
technology	148, 161, 162, 164-167, 169, 170
temperature	155
test	147, 162, 164, 171
theories	143, 148, 171
tides	161
time	146, 147, 162
transmission	155
ultraviolet	155
unbalanced forces	154
variable(s)	143, 144, 145
visible light	155
volcanos	159, 160, 168, 169
water	153, 160, 168, 169
water cycle	159, 160, 161
wavelength	155
weather	160, 166
weathering	160
weight	146, 147, 149
year	160