I searched it up and I got like one atom and something is that what you were looking for?
The answer is <span>increasing the surface area of Fe(s) and increasing the concentration of HCl(aq).
the rate of reaction can be increased if the interaction between the reactants in better. by increasing the surface area of a solid, such as Fe, you make more possible each molecule of Fe to interact with HCl. Also, by increasing the concentration of HCl, it mean there is more molecule of HCl to interact with Fe.</span>
The answer is zero also I suggest googling the questions there is a quizlet with the answers
I believe it is D as you are hearing the copper tube