As a star's evolution approaches the Type II supernova, we find
A) photo disintegration of iron nuclei begins at 10 billion K to ignite the supernova.
B) helium to carbon fusion takes at least 100 million K to start.
C) the heavier the element, the higher the temperature to fuse it.
D) the heavier the element, the less time it takes to make it.
E) All of the above are correct.
Question 2
Suppose you built a scale-model atom in which the nucleus is the size of a tennis ball. About how far would the cloud of electrons extend?
A) several kilometers B) several centimeters
C) a few meters D) to the Sun