Rigel, a blue supergiant, is 17 times more massive than the Sun and, therefore, is likely ________ in age.
Fill in the blank(s) with correct word
Question 2
What elements do astronomers consider heavy elements?
A) all elements besides hydrogen and helium
B) elements that are heavier than iron
C) elements that are heavier than uranium
D) elements that are heavier than hydrogen
E) elements that are heavier than carbon