In class, Ricardo rips up a piece of paper. Select the correct reason(s) that this is an example of a physical change.
The paper no longer has smooth edges.
The paper has not produced a gas when torn.
The paper's chemical composition has been changed.
The paper has not changed colors.
The paper is still paper with the same chemical makeup.

elements

explanation:

yes the other ones are right just show me a pic of ur face cuz u look hot

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !

some sources quote the lethal dose, for an average 170lbs opiate-naive individual is between 75 and 375 mg