The number of protons in a neutral atom equals the number of ELECTRONS.
A. is your correct answer
They are different because they use different frequency
The surface area to the volume ratio gets smaller as the cell gets larger. If the cell grows beyond a certain limit not enough material will be able to cross the membrane fast enough to accommodate the increased cellular volume.
Hope that helps
An acid has <em><u>c. more </u></em> hydrogen ions than a base.