Determine the number of protons in an isotope with the atomic number of 10 and the mass number of 21.

Answer

I think the answer is 10 because the atomic number represents the number of protons. Sorry if its wrong.

Explanation:

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 !

b.

the accuracy of the data.