Which element was detected in the Sun before it was found on Earth?
a. Hydrogen
b. Promethium
c. Helium
d. Argon
c
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? star has a radius similar to that of the Sun but half the Sun’s luminosity. What is the surface temperature of this star using this data?
a. 0.84 TSun b. 0.43 TSun c. 1.2 TSun d. 2.4 TSun
Energy Levels: Radio astronomers often study the radiation emitted by a hydrogen atom from a transition between the two hyperfine levels associated with the ground state. This radiation has a wavelength of 21 cm. What is the energy difference between the hyperfine levels? (1 eV = 1.60 × 10-19 J)
A. 5.9 × 10-6 eV B. 5.9 × 10-25 J C. 1.7 × 10-24 J D. 4.7 × 10-25 J
The best answer to both the flatness and horizon problems is:
A) the Steady State Theory. B) the GUT theory. C) the inflationary epoch. D) dark energy. E) decoupling.
According to Pauli's exclusion principle, how many electrons in an atom may have a particular set of quantum numbers?
A) 1 B) 3 C) 2 D) 4 E) 5