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Electrons that are further away from the nucleus have a greater attraction because the positive and negative charges are stronger than innermost electrons
It is important because they need to check each others work, this way they can get more accurate answers.
You need a control group in an experiment because if you did not have a control group your numbers or outcomes can cause an error because you wont have any numbers that are right to compare to. There will be too many things changed in the trial.
Answer:
When iron reacts with dilute H2SO4, iron (II) sulphate with the evolution of hydrogen gas is formed.