[chemicalLindsay]

Look i am doing fine in my srp except for one thing and that thing is classifying the variables as either independant , dependant or controlled variables and I cant find any worksheets on how to classify them. however after much pondering I have come to the conclusion with the classification of the variables of my topic (as shown below)where the investigation is "what causes iron to rust"
thanks and please feel free to comment onany mistakes I
may have made.

[Scratch-]

Surface area is a variable in the speed of the reaction.

[chemicalLindsay]

yes I know that thats why i haveput size of iron nail and amount of reactants as controlled variables.
Do you think thats good or should I be less specific.

[Scratch-]

Well size isn't the same as surface area, if you have the same amount of powdered metal the reaction will go a lot faster for example. Also nails are mostly steel and some may have different materials mixed in than others, a lot of steel is plated in zinc (called galvanizing) that prevents rusting, but I guess that would go under type of reactants.

[chemicalLindsay]

yes I must have overlooked that about surface area.
thanks for that .do you think surface area of reactants sounds better for surface are,and yes I am using non galvanised steel nails.
If anyone feels it necessary to comment please do so