1. 19.9 Review – The Universe

2. Heliocentric vs. Geocentric
Geocentric Model – earth in the center and everything else revolves around it
Heliocentric Model – Earth and all the other planets revolve around the sun
Developed by Copernicus

3. Solar eclipse vs. Lunar eclipse
Solar – moon casts a shadow on the earth
Lunar – earth casts a shadow on the moon

4. Asteroid vs. comet
ASTEROIDS Large rock masses that orbit the sun, from the asteroid belt COMETS Dusty pieces of ice and rock that vaporize when they pass near the sun;

5. 4. Characteristics: A. Mercury: closest planet to sun, 88 day year
B. Venus: Thick atmosphere, 243 day rotation
C. Earth: Water, Life!
D. Mars: red due to iron, seasons, Earthlike
E. Ceres: dwarf planet in asteroid belt
F. Jupiter: largest, great red spot
G. Saturn: rings
H. Uranus: axis rotates at tilt of > 90°
I. Neptune: blue due to methane, 165 yr. rev.
J. Pluto: dwarf planet, axis rotates at tilt of > 90°
K. Eris: dwarf planet, located in Kuiper belt

6. 5. List 3 Earth events that involve the moon
Solar eclipse Lunar eclipse Tides

7. 6. Explain the difference between meteoroid, meteor and meteorite.
METEOROIDS
A small rock that travels through the solar system
METEOR – a meteoroid that burn up in the earths atmosphere
METEORITE – a meteoroid that makes it to the earth’s surface

8. 7. Where is the asteroid belt located?
Between the terrestrial planets and the gas giants; between Mars and Jupiter

9. 8. Where is the Kuiper Belt located?
Beyond Pluto

10. 8. Atom Counts
2NH3 + O2 NO2 + H2O

11. 9. Main evidence for Big Bang
The universe is still expanding:
Hubble’s Law

12. 10. Explain the difference between spring & neap tides
spring-sun & moon
Aligned so stronger
Gravitational pull
Neap-sun & moon
at right angle to Earth

13. 11. Lists: Terrestrial: Dwarf: Gas Giants: Mercury Venus Earth Mars
Ceres
Pluto
Eris
Gas Giants:
Jupiter
Saturn
Uranus
Neptune

14. 12. Full , half, new moon

15. 13. Umbra vs. penumbra Umbra-darkest part of the shadow (inner)
Penumbra-lighter shadowed area (outer)

16. 14. What nuclear reaction produces the suns energy?
Nuclear fusion

17. 15. Star properties: Color and temperature Brightness Size and mass
Composition

18. 16. How does the life of a star begin?
Stars form out of clouds of hydrogen and helium and dust called nebulas.
As gravity pulls these elements together they began to heat up.
The heat fuels nuclear fusion reactions that create heavier elements, heat, and light.

19. 17. What colors… The color of a star indicates the temperature
Blue stars have a surface temp of 30,000 K
Blow torch
Yellow stars have a surface temp of 6000 K
A flame
Red stars have a surface temp of 3000K
Cooling embers in a fire

20. 18. What are the 4 galaxy shapes?
Spiral – a bulge of stars at the middle with arms extending outward like a pinwheel
Barred-Spiral Galaxies – a spiral galaxy with a bar through the center and the arms are extending from the bar
Elliptical Galaxies – are spherical or oval shaped
Irregular Galaxies – have a disorganized appearance.

21. 19. H-R diagram

22. 20.When a star runs out of uel, what might it become?
It may become a white dwarf, a neutron star, or a black hole

23. 21. Doppler…
The Doppler effect explains that objects moving away from Earth have longer wavelengths, which produce red light.

24. 22.
The doppler effect explains that objects moving toward Earth have shorter wavelengths, which produce blue light

25. 23. Define Hubble’s Law:
Hubble’s Law states that the speed at which a galaxy is moving away is proportional to its distance from us.

26. 24. List the technology used in space exploration
Telescopes
Visual – use visible light
Radio – use radio waves to retrieve information from space probes.
X-Ray – use shorter wavelength than visible light
Computers managing data.
Space Probes collect information and materials.

27. 51. This represents the number of molecules present in a compound.
a. reactant
b. product
c. coefficient
d. subscript
52. balanced: H2 + O2  H2O

28. Extra credit:
53. Isotopes on one element are changed into isotopes of another element in a
a. nuclear reaction
b. chemical reaction
54. This type of reaction may involve protons, neutrons, and electrons.

29. 55. What percentage of a material remains after 2 half-lives?
b. 50%
c. 25%
d. 12.5%