Are Na+ and Cl- ions smaller than a water molecule?

Answer 1

I find it highly interesting that polar H2O molecules can diffuse through the plasma membranes, while ions such as Na+ and Cl- cannot and must be transported/pumped across the membrane.

Also, compare the atomic/molecular weights of each. And what about the electron shell(s) size on each? Does the larger number of electron shells on the ions outdo the steric size of 3 smaller atoms?

I'm gonna say the water molecule is smaller, but don't know with absolute certainty... don't know the answer to my last question.

Answer 2

Both sodium and chlorine in any form are smaller than a water molecule.

Answer 3

yes