Why did Galileo's observations of moons orbiting Jupiter disagree with geocentric model of the universe of his time?
a. The moons moved in non-circular orbits about Jupiter.
b. The moons did not appear to orbit the Sun.
c. The moons did not appear to orbit the Earth.
d. The moons appeared to be too small, and therefore too far away, to be considered part of the solar system.
Question 2
In the proton-proton chain
a. no neutrinos are produced.
b. energy is released because a helium nucleus has a greater mass than a hydrogen nucleus.
c. no photons are produced.
d. carbon serves as a catalyst for the nuclear reaction.
e. energy is produced in the form of gamma rays and the velocity of the created nuclei.