Uranium serves as the source of the Sun's energy because
a. uranium atoms can be fissioned into lighter atoms and energy.
b. uranium atoms can be fused into helium and energy.
c. uranium atoms can be fused into hydrogen and energy.
d. none of the above because fusion of hydrogen atoms serves as the Sun's source of energy.
e. none of the above because fusion of helium atoms serves as the Sun's source of energy.
Question 2
The first modern astronomer to propose a heliocentric model for the solar system was ___________________ _.
Fill in the blank(s) with correct word