Earth is about 150.000.000 km from the Sun. Its input of solar energy per square meter is I. Mars is about 228.000.000 km from the Sun. Which of these most likely represents the input of solar
energy per square meter on Mars?

a. 0.287
b. 0.431
c. 0.657
d. 0.991

Cells in the nervous system have a potential difference of 70 mv across the cell membrane separating the interior of the cell from the extracellular fluid. this potential difference is maintained by ion pumps that move charged ions across the membrane. is this an emf? select the correct answer and explanation. 1)no. the ion pumps cannot separate charges; thus, they cannot create a potential difference. 2)yes. the ion pumps cannot separate charges, but they still can create a potential difference. 3)yes. the ion pumps can actively separate charge; thus, they can create a potential difference. 4)no. the ion pumps can separate charges, but they cannot create a potential difference.