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Home Q & A Board Science-Related Homework Help Physics Astronomy
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RedManchester23 RedManchester23
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6 years ago
The earliest Homo sapiens appeared about
 
  A) 25 million years ago
  B) 6 to 7 million years ago
  C) 200,000 years ago
  D) 545 million years ago

Question 2

A radioactive isotope is
 
  A) an unstable nucleus that gives off radio waves
  B) a nucleus that formed from the fusion of two other nuclei
  C) a stable nucleus that is formed from the fission of a large unstable nucleus
  D) an unstable nucleus that spontaneously breaks apart

Question 3

At the top of the HertzprungRussell diagram we find
 
  A) red giant stars
  B) white dwarfs
  C) supergiant stars
  D) main sequence stars
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mlevans624mlevans624
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6 years ago
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6 years ago
God bless you! Helped my grade so much.
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