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Home Q & A Board Science-Related Homework Help Physics Astronomy
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Thisisdumb Thisisdumb
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6 years ago
Mars is best viewed from Earth when it is at:
 
  A) perihelion.
  B) opposition.
  C) conjunction.
  D) aphelion.
  E) None of the above.

Question 2

A planet (or comet) will speed up as it approaches the Sun.
 
  Indicate whether the statement is true or false

Question 3

The energy required to ionize a hydrogen atom whose electron is in the ground state (energy level 1 ) is:
 
  A) 10.2 eV.
  B) 12.1 eV.
  C) 12.75 eV.
  D) 13.1 eV.
  E) 13.6 eV.

Question 4

In the collapsing cloud fragment stage (stage 2 ) of star formation, the size of the cloud fragment is about:
 
  A) the size of the solar system.
  B) 10 times the size of the solar system.
  C) 100 times the size of the solar system.
  D) 1,000 times the size of the solar system.
  E) 10,000 times the size of the solar system.

Question 5

When does a protostar become a true star?
 
  A) when the star is 1 million years old
  B) when the central temperature reaches 1 million Kelvin
  C) when nuclear fusion begins in the core
  D) when the thermal energy becomes trapped in the center
  E) when the stellar winds and jets blow away the surrounding material
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tcshepherd13tcshepherd13
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6 years ago
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Thisisdumb Author
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#2
6 years ago
Thank you for answering correctly!
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