9. a substance dissolves in water by breaking up into smaller pieces. these pieces of the same substance spread throughout the water. this process is known as
10. stirring increases the rate of solution of a solid in a liquid because solute particles in solution are moved the surface of the solute.

Answer :

(9) This process is known as diffusion.

(10) The answer is, the solute particles in solution are moved away from the surface of the solute.

Explanation :

For 9 :

Diffusion : It is a process in which the solute particles flow from a solution of high concentration to a solution of low concentration.

Or we can say that, the diffusion is the movement of a molecule or substance from the area of high concentration to the area of low concentration.

Or we can say that, the spreading of the substance throughout the solution is known as diffusion.

For 10 :

Stirring is a process that increase the rate of solution of a solid in a liquid. When the solute particles dissolve in solution then they are moved away from the surface of the solute by stirring process and increase the rate of solution of a solid in a liquid.

the unequal cytoplasmic division that  results  in  one egg  and three polar bodies ensures that a fertilized  egg has  ample nutrients  forits journey  to  the uterus.