The functiоning оf cells depends оn vаrious elements, such аs Nа, K, and Ca, that are dissolved in water as ions. These ions move in and out of 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 (K+) channel carries a current of 1.80 pA. How many potassium ions pass through if the ion channel opens for 1.0 ms?