Problem 27 - Chemistry: An Atoms-Focused Approach

Question

Which ion channel must accommodate the larger cation, a potassium or a sodium ion channel?

Step-by-Step Solution

Answer

Answer: The potassium ion channel must accommodate the larger cation.

Step 1: Recall the atomic radius of potassium and sodium ions

The atomic radius of potassium ion (K+) is approximately 152 pm, while the atomic radius of a sodium ion (Na+) is approximately 102 pm. Keep in mind that these values are rough estimates and might slightly vary in different sources.

Step 2: Compare the sizes of potassium and sodium ions

To determine which ion channel needs to accommodate the larger cation, compare the atomic radii of K+ and Na+ ions. Since the atomic radius of K+ (152 pm) is larger than the atomic radius of Na+ (102 pm), K+ ions are larger than Na+ ions.

Step 3: Determine the ion channel with larger accommodation requirements

The ion channel that must accommodate the larger cation will be the one involving the larger ion. Thus, a potassium ion channel has to accommodate a larger cation than a sodium ion channel because potassium ions (K+) are larger than sodium ions (Na+). So, the potassium ion channel must accommodate the larger cation.