How many potassium ions pass through if the ion channel opens for 1.0 {\rm ms}?

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The discussion revolves around calculating the number of potassium ions that pass through an ion channel when it opens for 1.0 ms, given a current of 1.8 pA. The calculation involves determining the total charge (1.8E-15 C) and dividing it by the charge of a single ion (1.6E-19 C), resulting in approximately 11,250 ions. There was confusion regarding significant figures, as the platform required an answer in two significant figures. Ultimately, entering "1.1e4" was accepted as the correct response. This highlights the importance of understanding both the calculation and the formatting requirements in scientific submissions.
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Homework Statement


The biochemistry that takes place inside cells depends on various elements, such as sodium, potassium, and calcium, that are dissolved in water as ions. These ions enter cells through narrow pores in the cell membrane known as ion channels. Each ion channel, which is formed from a specialized protein molecule, is selective for one type of ion. Measurements with microelectrodes have shown that a 0.30-nm-diameter potassium ion ({\rm{{\rm K}}}^{\rm{ + }} ) channel carries a current of 1.8 {\rm pA}.

How many potassium ions pass through if the ion channel opens for 1.0 {\rm ms}?

Homework Equations



Delta charge (Q)=Current (I) * delta time
1 ion = 1.6E-19 C



The Attempt at a Solution


Delta Q=1.8E-12*1E-3=1.8E-15C

1.8E-15C/1.6E-19=11,250

Mastering physics wants 2 sig figs, so entered "11,000" which is wrong.
 
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deborahcurrie said:
1.8E-15C/1.6E-19=11,250

Mastering physics wants 2 sig figs, so entered "11,000" which is wrong.

It looks right to me. Is it possible to enter "1.1e4"?
 
That did it. Thanks for thinking of the tip!
 

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