24.In order to go to a lower energy orbit, an electron a.Must disappear
b.Must combine with other electrons
c.Lose energy of a specific amount
d.Must be transferred to another atom

C. It has to lose energy to move to a lower orbit

Explanation:

Entropy refers to the degree of disorderliness of system. Basically it refers to how random a system is.

Gong through the options.

A. The phase change is from solid to liquid. Liquid has a greater degree of disorderliness compared to solid hence entropy is increasing.

B. The phase change is from solid to gas. Gas particles has a greater degree of disorderliness compared to solid hence entropy is increasing.

C. The phase change is from aqueous to liquid. Aqueous solutions has a greater degree of disorderliness compared to liquid hence entropy is decreasing.

D. The reactant side has; solid + gas. In the product side, there is only gas. The product side has a greater degree of disorderliness hence the entropy is increasing.

E. The entropy of the product is greater than the entropy of the reactants hence entropy is increasing.

F.  The phase change is from aqueous to solid. Aqueous solutions has a greater degree of disorderliness compared to solid hence entropy is decreasing.