Please please help I am so confused

Avariable that is not being directly tested during an experiment should be changed varied experimented controlled

Idid a lab for chemistry where we put nails in a copper (ii) chloride solution. 1. why did the reaction stop? which reactant was used up? how do you know? 2. describe what was happening to the atoms of iron and copper during the reaction. what is this type of reaction called? 3. what would happen to the ratio of copper to iron if you had placed more nails in the beaker? if you had let the reaction go for less time? 4. what is the accepted ratio of copper atoms to iron atoms in this reaction? account for differences between your experimental value and the accepted value. write the balanced equation for the reaction.

Timed ! in which of these statements are protons, electrons, and neutrons correctly compared? quarks are present in protons and neutrons but not in electrons. quarks are present in protons, neutrons, and electrons. quarks are present in neutrons and electrons but not in protons. quarks are present in protons and electrons but not in neutrons.