Both isotonic and isosmotic refer to the strength of the solution,  for example, how much solute is dissolved in the solution. Isotonic  refers to the ionic strength of a soâ¦lution while isosmotic refers  to the number of molecules of solutes in a biological solution, for  example, sugar concentration.
The egg is strongest from point to point and easily crushable at the sides. Breaking an egg with steady equal pressure at each end of the egg is remarkably hard to do when considering the thin shell involved.
If the yolk is breaking easily then the eggs are either older eggs or lower grade eggs. The highest grade eggs is AA which not only looks at shell quality, but also the yolk quality. AA eggs should have a tall firm yolk. Over time the yolk becomes less firm and resilient causing breaking when it's cracked.