Can y’all help me with #18 please

Two changes are described below. a green banana turns yellow and ripens. a layer of rust forms on an iron nail. which statement is true about the two changes? a) both are chemical changes because new substances are formed. b) both are physical changes because only the physical state of the substances change. c) a is a physical change due to a change of state, but b is a chemical change because new molecules are formed. d) a is a chemical change due to a change of state, but b is a physical change because new molecules are formed.

Using the results from the two previous questions: solution one: 1 x 10-4 m solution two: 1 x 10-7m the hydrogen ion concentration of these two solutions differ from each other by a factor of

Select the correct answer from each drop-down menu. in a reversible reaction, the forward reaction takes place the reverse reaction. such a reaction, on reaching equilibrium, will have .