Example :

If you use the subscript (aq) (=aquaris) , this means that the substance is in a solution.
Subscripts:
-aq-this means that the substance is in a solution
-s-this means that the substance is a solid(or precipitate)
-l-this means that the substance is a liquid
-g-this means that the subtance is a gas
Answer:
Copper(II) chloride (CuCl2) reacts with several metals to produce copper metal or copper(I) chloride (CuCl) with oxidation of the other metal.
Explanation:
Bond energy is basically how much energy it takes to break that molecule apart. The main things that affect bond energy is electronegativity and the number of bonds. I believe the correct answer is C=O. It <span>has the greatest bond energy, because it is harder to break apart a double bond than a single bond.</span>
Option E, 2, 7, 4, 6. The type of reaction is combustion reaction, as oxygen is being reacted with C2H6 to form new compounds.
Let me know if you need any further explanation :))
-T.B.