What is atomic weight?

The atomic mass is the mass of an atom. Although the SI unit of mass is the kilogram, atomic mass is often expressed in the non-SI unit atomic mass unit or unified mass or dalton, where 1 amu or 1 u or 1 Da is defined as 1⁄12 of the mass of a single carbon-12 atom, at rest.

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 !

explanation: it gains negative electrons, therefore becoming negatively charged. as charge cannot be created, nor destroyed, only transferred, this leaves the wool positive. now that they have opposite charges, the two items attract.