A 175 g lump of molten lead at its melting point (327° C) is placed into 55.0 g of water at 20.0°C. The specific heat of
lead is 130J/kg°C and the Hf of lead is 20,400 J/kg. When
the lead has become solid but is still at the melting point, what
is the temperature of the water?

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.