Most pulsars have a measured mass of
A) about 1.4 solar masses.
B) 5.2 solar masses.
C) greater than 10 solar masses.
D) less than 1.0 solar masses.
E) between 2 and 4 solar masses.
Question 2
A stars exhibit strong hydrogen absorption lines because the surface temperature of 10,000 K is high enough to place most hydrogen in an excited, but not yet ionized, state.
The transitions from this excited state then correspond to visible light wavelengths. Which of the following statements is a plausible explanation for why G stars exhibit weak hydrogen absorption lines?
A) G stars contain very little hydrogen.
B) At these high temperatures, nearly all the hydrogen is ionized, and unable to interact with light.
C) G stars are too cool to excite hydrogen atoms to the first energy level from which they can then absorb visible wavelengths of light.
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