When a fuel cell operates, the energy transformation within the cell itself is
A) thermal energy to electric energy.
B) chemical energy to electric energy.
C) electric energy to chemical energy.
D) thermal energy to kinetic energy.
E) chemical energy to thermal energy.
Question 2
The distance to the sun is about 150 million km. Expressed in powers of ten, this is
A) 1.5 106 km.
B) 1.5 108 km.
C) 1.5 10-8 km.
D) 1.5 10-6 km.
E) None of the above.
