Janice mixed in orange solution of sodium sulfide with a clear solution of hydrochloride acid. she noticed after a minute that the solution smelled something like a rotten eggs. what could she reasonably infer from the order released by the solution

That the hydrochloric acid reacted with the sodium sulfide to produce the same gas that is formed from rotten eggs.  

Explanation:

The equation for the reaction for the reaction is

     Na₂S(aq)     +       2HCl(aq)         ⟶    2NaCl(aq)     +          H₂S(g)

sodium sulfide + hydrochloric acid ⟶ sodium chloride + hydrogen sulfide

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 !

the electron configuration that you gave me has 16 electrons ergo it has 16 protons ergo it is the element sulfur.