What happens to the core of a star after a planetary nebula occurs?
A) It contracts from a protostar to a main-sequence star.
B) It breaks apart in a violent explosion.
C) It becomes a white dwarf.
D) It becomes a neutron star.
E) none of the above
Question 2
The average density of the Moon is less than that of the Earth.
Indicate whether the statement is true or false