A group of students are asked to design and build a device which will keep ice from melting. How could they best prevent heat from transferring to the ice by convection? A) Paint it black to absorb heat.

B) Paint it white to reflect radiation

C) Fill in all cracks to prevent hot air from entering

D) Use an insulator to prevent heat from entering

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.