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.
Question 2
The ____ produce(s) tides on the Earth.
a. Moon alone
b. Sun alone
c. Moon and Sun