8th Grade Science
1st Semester Exam Study Guide
SCIENTIFIC METHOD
1. Why it is important for scientists to be skeptical? If a scientist is skeptical of the results of an experiment,
what should he usually do?
Skepticism is one of the most valuable tools in science. Continual questioning of ideas and results is a means
of overturning long-held assumptions and uncovering new ideas. A skeptic in science will continually review
the credibility of a scientific result or idea
2. What makes an experiment valid?
When the results give validity to the question (hypothesis) that is being asked or tested.
3. What is the difference between qualitative and quantitative data?
Qualitative Data is used to describe something using your 5 senses. Quantitative Data is when you describe
something using numbers.
EARTH SCIENCE
4. What are the 4 layers of the Earth?
Inner core, outer core, mantle and crust
5. What are the two types of crust? What types of rock are they made of? Which type is more dense?
Continental – granite and Oceanic – basalt, oceanic is more dense
6. Which layer of the Earth is made of the crust plus the upper mantle (this layer is rigid and brittle like a jolly
rancher)?
Lithosphere
7. Which layer of the Earth is plastic and flowing (like silly putty)?
Asthenosphere
8. Which layer (asthenosphere or lithosphere) is broken into large pieces called plates?
Lithosphere
9. Which layer (asthenosphere or lithosphere) carries the plates?
Asthenosphere
10. What process causes the tectonic plates to move?
Convection currents
11. What are the three types of plate boundaries? Describe how the plates move at each (toward each other,
away from each other, or slide past each other).
Convergent – Plates come together/collide, Divergent – plates move away from each other/divide, Transform –
plates slide past each other/shear
12. Describe what happens when the following plates collide:
a. Continental crust collides with continental crust – mountains
b. Continental crust collides with oceanic crust – subduction zone, oceanic trench and volcanoes, rift
valleys
c. Oceanic crust collides with oceanic crust - volcanoes
13. Where are ALMOST all volcanoes formed?
Volcanoes are most commonly found at subduction zone boundaries. This is where the thinner oceanic plates get
pulled under the thicker continental plates. As the plates go deeper, they melt and form pockets of magma which
can cause mountains to be built and as the hot magma rises, it erupts out of volcanoes.
14. What is a hot-spot volcano?
This is an extra hot plume of molten rock which causes the earth’s crust to thin allowing molten rock to escape
onto the surface. The movement of the earth’s tectonic plates means that volcanoes form a trail along the earth’s
surface.
15. What occurs when too much stress builds up at a plate boundary and the rock finally breaks?
Earthquake
Weather
16. What are the 4 air masses that affect the United States? What type of air is each (temperature and
humidity)?
Continental Polar, Continental Tropical, Maritime Polar, Maritime Tropical
17. What are the symbols for each type of front (cold, warm, stationary, occluded)? What type of weather
comes with each type of front?
18. How can you tell which way a front is moving?
The direction in which the symbols are moving toward
19. What are the symbols for high-pressure and low-pressure symbols? What type of weather is associated
with each?
20. Where do hurricanes form? What causes a hurricane to strengthen? To weaken?
in the Atlantic off the African coast, in the Gulf of Mexico or in the Caribbean
Strengthen: Sea surface temperatures warmer than 79 degrees Fahrenheit (26 degrees Celsius), Low vertical wind shear,
Warm moist air, Ocean area along the projected storm track
Weaken: Cooler Sea surface temperatures less than 79 degrees Fahrenheit (26 degrees Celsius)
High vertical wind shear
Dry air
Land masses along the projected storm track
21. Which global wind steers hurricanes and in which direction?
Trade winds
22. Are hurricanes associated with high pressure or low pressure?
Low Pressure
23. Be able to interpret the Saffir-Simpson scale.
Astronomy
24. What are the two ways that Earth moves through space?
Rotation and Revolution
25. What causes day and night on Earth?
Rotation of the Earth around the sun
26. What causes climate zones on Earth?
Revolution of the Earth around the sun
27. What causes seasons on Earth?
The earth's spin axis is tilted with respect to its orbital plane. This is what causes the seasons. When the earth's
axis points towards the sun, it is summer for that hemisphere. When the earth's axis points away, winter can be
expected.
28. Be able to look at a diagram and determine what season it is in the Northern/Southern hemisphere?
29. What is the difference between the solstices (winter and summer) and the equinoxes (spring and fall)?
The solstices are defined as the times at which the sun is furthest from the celestial equator, and hence the
difference in length between night and day is greatest. The winter and summer solstices usually occur around the
21st December and 21st June respectively, but are subject to change due to the earth's orbit being slightly longer
than our 365 day calendar. The equinoxes are the times at which the sun is closest to the celestial equator,
resulting in day and night being of almost equal duration. They occur around the 20th March (the vernal equinox)
and the 22nd September (the autumnal equinox), though are subject to variation for the reasons stated above.
30. What is the order of the Electromagnetic Spectrum (in terms of wavelength, frequency, and energy)?
Radio, Micro, Infrared, Visible Light, Ultraviolet, X-Ray, Gamma
31. What types of radiation can damage the cells of living things?
32. What types of radiation are blocked by Earth’s atmosphere?
Visible, Infrared, Microwaves, and Radio CAN pass through, but UV is absorbed by Ozone and X-rays and
Gamma Rays have a hard time going through the Earth's Magnetosphere.
33. What type of radiation is also known as heat?
Infrared
34. Why must astronomers place some telescopes in space?
Telescopes are placed into orbit around the Earth or are sent farther out into space to get a clearer view of the
Universe.
35. List the hierarchical structure of objects in the universe.
36. What is the name of the theory that explains the formation of the universe?
37. How do astronomers know that the universe is expanding?
Physics
38. What is the formula used to calculate speed?
39. On a distance vs. time graph, draw the shapes that represent the following: at rest, constant speed,
accelerating, decelerating
40. On a speed (velocity) vs. time graph, draw the shapes that represent the following: constant speed,
accelerating, decelerating
41. What are two forces that affect the motion of objects on Earth?
42. Write Newton’s three laws of motion. Give an example of each.
43. What is the math equation that represents Newton’s Second Law?