Question

Please help and show work. I keep getting the wrong answers for these problems

1. Cell membranes contain channels that allow Na + ions to rush in. Consider a channel that has a diameter of 2.91 nm and a length of 13.5 nm. If the channel has a resistance of 18.5 GΩ, what is the resistivity ? of the solution in the channel?

2. What is the resistance of a 54.154.1-m-long aluminum wire that has a diameter of 8.79 mm8.79 mm? The resistivity of aluminum is 2.83×10−8 Ω · m2.83×10−8 Ω · m.

resistance:

3. A certain single ion channel is selectively permeable to K+K+ and has a resistance of 1.15 GΩ1.15 GΩ , therefore a current of potassium ions through the channel is possible. During an experiment, the channel is open for approximately 1.50 ms1.50 ms while the voltage across the channel is maintained at 85.5 mV85.5 mV . How many K+K+ ions travel through the channel during this time?

number of K+K+ ions:

Answer 1

mention in comment if you have any doubt