Neutral hydrogen atoms are best studied from their energy given off as
A) 21-cm waves in the radio region.
B) 0.2 nm as X-rays.
C) 121.3 nm as Lyman alpha emission in the UV.
D) red hydrogen alpha emission, at 656.3 nm.
E) Neutral hydrogen gives off no detectable radiation, since it is cold, not hot.
Question 2
Which common gas is less abundant in the top of Saturn's atmosphere, compared to what we observe at Jupiter?
A) methane B) nitrogen C) helium D) hydrogen E) argon
