The answer is A, because of the chemical reaction taking place color can change (as in this case). Hope it helps!
Answer:
Copper is typically a solid and has a coppery, bronzy color. It is a metal and has a relatively high melting point. It has a strong luster and can conduct electricity.
So the equation is balanced, meaning they have the smallest amounts of each element in the reactants to create the products.
So, 2 moles of H2S (the coefficient) contributes to 2 moles Ag2S, which is why the ratio is 2:2.
I hope that made sense.
