I think the answer is mercury
Answer:
A physical change, such as a state change or dissolving, does not create a new substance, but a chemical change does. In a chemical reaction, the atoms and molecules that interact with each other are called reactants. In a chemical reaction, the atoms and molecules produced by the reaction are called products.
Answer:
Reverse the 
reaction
Explanation:
Reactions:
Overall:
As can be seen, in the overall reaction we have 
in the reactants like in the second reaction and 
in the products. The is in the first reaction but as a reactant so we need to reverse that reaction:
Combining:
Answer: In the immune responds B,D are correct
Explanation:
I know this because i already learned it
