Question

what is an isotonic solution

Answer 1

An isotonic solution is when two solutions have the same osmotic pressure across a semipermeable membrane. This lets the movement of water be free across the membrane without changing the concentration of solution on a side. 

Answer 2

Answer:

A solution when there is no net movement in the water.

Explanation:

Since the amounts of solute inside and outside the cell are even, the cells don't swell or shrink.