Answer:
C. The rate of the reaction begins to decrease as the reactants are used.
Explanation:
a p 3 x
Potassium and Chloride forms an ionic bond.
(K+) + (Cl-) = KCl
Potassium is under Group IA (Alkali Metal), wherein elements under this group can easily lose electrons.
Chlorine is under Group VII (Halogens), in which these elements can gain electrons easily.
The inner shell electrons on potassium will merge with the outer shell of electrons of chlorine to make potassium chloride.
D) Physical Change, I would argue, because you can reverse this change by boiling off (evaporating) the water. But there are arguments for both physical and chemical change being what occurs.
A physical change results in a change of the material's appearance, but no new chemical products result. A chemical change involves a chemical reaction, with new substances produced as a result of the change.