The best answer choices can be A.because it reduction he eletrolytic from positive
Fireworks
An exothermic reaction is one where the products have lower energy than the reactants, so the reaction yields energy. The chemical compounds present in firework fuel release a lot of energy upon oxidation. Photosynthesis is endothermic, settling of silt is not a chemical reaction, it is a physical change. Finally, the bubble formation in soda is not exothermic; otherwise, the sodas would become very hot very fast.
Chemical change occur when two substances are combined and produces a new substance or decomposes into two or more substances which are entirely different from the original two substances.
There are three types of chemical changes. These are 1) Inorganic Changes, 2) Organic Changes, and 3) Biochemical Changes
Here are some examples of chemicsal changes.
If you combine Sodium and Water, chemical changes causes decomposition into Sodium Hydroxide and Hydrogen.
Sodium + Water ==> Sodium Hydroxide and Hydrogen
Na + H2O ====> NaOH and H
Another example of chemical change is:
Carbon Dioxide and Water will decompose into Sugar and Oxygen
Carbon Dioxide + Water ==> Sugar and Oxygen
CO2 + H2O ==> CnH2nOn (where n is between 3 and 7) and O
Reaction:

Magnesium is a stronger reducing agent than copper and is thus able to reduce copper(II) oxide.
Products of the reaction: Magnesium oxide and metallic copper.
Answer: <span>A reaction progress curve has three peaks and two valleys between the peaks. This curve describes a reaction mechanism that involves
<u>three elementary reactions</u>.
Explanation: I have drawn the progress curve with three peaks and two valleys. In fact the peaks shows higher energy and valleys show lower energies. So, Let suppose we react
A and
B. This reaction between A and B results in the formation of
C. In this reaction the energies of A and B are less, and during the progress of reaction they cross a transition state of higher energy and forms product C with lower energy which is present at lower valley. This was first reaction. Other two reactions will be followed by conversion of C to
D and conversion of D into
E.</span>