Answer:
The coefficient tells you how many molecules of that substance there is. The subscript tells you what the substance it. It tells you the the amount of each element there are in the molecule. Changing it would change the substance itself.
B - Evolve into the closest species on the tree’s trunk
It forms covalent compounds
Answer: 
Explanation:
A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
A double displacement reaction in which one of the product is formed as a solid is called as precipitation reaction.
The balanced chemical equation is: