Download 8th Grade Midterm Test Review

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8
Grade Midterm Test Review
1. What limits what scientists can
study in their work?
• Scientists can only study phenomena that they
can observe
2. What personal trait do scientists mainly
depend on when they design an experiment?
• Creativity
3. When scientists develop a theory,
what is the purpose for repeat trials?
• To repeat experiments and verify results
4. Why is astronomy science while
astrology is pseudoscience (not science)?
• Astrology is pseudoscience because there is
no valid scientific data to support it.
5. What is the reason for the increased
popularity of hybrid cars and cars that use
alternative fuels?
• The high levels of carbon dioxide in the
atmosphere
6. The terrestrial planets have a (lower or
higher) density than gas giant planets?
• The terrestrial planets have a higher density
than the gas giant planets
7. A star system made up of two pairs
of stars is called a ______ star system.
• Quadruple
8. Apparent magnitude is how bright a
star looks (appears) from __________.
• Earth
9. How far is a light year?
• 9.5 trillion km
10. Rank the following star apparent magnitudes
from dimmest to brightest: -1.44, 1.23, -0.31,
9.54
• 9.54, 1.23, -.31, -1.44
11. Which of the following is farthest from
Earth? Mars, the sun, the moon, Milky Way
galaxy, or Andromeda galaxy?
• Andromeda galaxy
12. Rank the following in order from
largest to smallest: galaxy, star, universe,
planet
• Universe, Galaxy, Star, Planet
13. Red and yellow stars have a relatively (hot or
cool) temperature while blue and white stars
have a relatively (hot or cool) temperature.
• Red & Yellow Stars= Cool
• Blue & White Stars= Hot
14. What characteristic of stars is
measured by luminosity?
• Brightness
15. After the sun’s hydrogen is consumed in five
billion years or so, what will be its primary fuel?
• Helium
16. When distance between objects
increases, gravitational force (increases or
decreases).
• Decreases
17. What type of surface do terrestrial
planets have?
• Solid
18. Which planets in the solar system
have rings?
• Saturn, Jupiter, Uranus, & Neptune
19. A small rocky body that travels
through space is called a __________.
• Meteoroid
20. An unbalanced force that makes objects
move in an elliptical path is called ___________
force.
• Centripetal
21. The process that joins two atomic nuclei to create a
new nucleus and an enormous amount of energy is
called _____________ ___________.
• Nuclear Fusion
22. The geocentric theory has ________ in
the center while the heliocentric theory
has _______ in the center.
• Earth in the center= geocentric
• Sun in the center= heliocentric
23. What lies between Mars and
Jupiter?
• The asteroid belt
24. Why is a year on Mars longer than
a year on Earth?
• Mars is farther from the Sun than Earth is.
25. Arrange the following in the correct order in the
formation of the solar system: protostar, planetesimal,
terrestrial planet, protoplanetary disk
• Protoplanetary Disk to Protostar to
Planetesimal to Terrestrial Planet
26. Why are dwarf planets round?
• Dwarf planets are round because of their own
gravity
27. About how often does sunspot
activity peak?
• The length of a sunspot cycle is about 11 years
28. The path Earth travels as it revolves
around the sun is called its _________.
• Orbit
29. One complete rotation of Earth is
called a _________.
• Day
30. Why can you see the surface of the
moon from Earth?
• Light from the sun is reflected by the moon’s
surface
31. What accounts for the differences in
the appearance of the moon from day to
day?
• The position of the moon in its orbit around
the Earth
32. Be able to identify independent
and dependent variables.
• Independent= factor that is deliberately
manipulated in an investigation
• Dependent= factor that changes as a result of
manipulation of one or more independent
variables
33.What is the difference between apparent magnitude
and absolute magnitude? How is it possible for a star
that is actually brighter than another to appear
dimmer?
• Apparent magnitude is how bright the star
appears to someone on Earth, and absolute
brightness is how bright the star is regardless
of its distance from Earth. A star that is
brighter than another star, but much farther
away from Earth, can appear dimmer because
of its distance from Earth.
34. What makes up a solar system?
• A solar system consist of a star and all the
objects in orbit around it.
35. If a scientist examines a star that is the same
color as the sun, what can the scientist assume
about he temperature of the star?
• The scientist can assume that the star may
have a temperature that is similar to the Sun’s
because it is the same color
36. What makes up and holds together
a galaxy?
• A galaxy is made up of billions of stars,
planets, gas and dust.
• A galaxy is held together by gravity
37. When scientists refer to a light year,
what do they mean? Be sure to quantify
your answer.
• A light-year is the distance light travels in one
year, about 9.5 trillion km.
38. How did the terrestrial planets
form?
• The terrestrial planets developed from
collisions and mergers of rocky planetismals
39. Identify and explain the process by
which the sun releases energy.
• Sun releases energy through nuclear fusion.
• Nuclear fusion is the nuclei of two small atoms
coming together to form a larger nucleus
• Energy is formed from matter
40. Why might early astronomers have
thought that Earth was the center of the
universe?
• They were unable to see parallax without a
telescope
41. How did the solar system form?
• The solar system formed from a solar nebula,
which is a rotating cloud of gas and dust. As the
nebula collapsed, the matter in the nebula
condensed to form a central core and a
protoplanetary disk. The central core became a
protostar that was compressed by gravity until it
became hot enough to begin nuclear fusion, at
which point it became a star (the sun). In the
protoplanetary disk, the matter collided to form
planetesimals, which slowly became larger until
they were large enough to be planets.