Answer:
A
Explanation:
hail will fall push it back up making it bigger comes back down
The reaction of iron sulfide (FeS) with hydrochloric acid (HCl) results in the formation of ferrous chloride (FeCl2) and hydrogen sulfide (H2S) gas. The reaction can be shown as follows:
FeS (s) + HCl(aq) ---- FeCl2(s) + H2S(g)
The bubbles indicate the formation of H2S gas which is a chemical change. The formation of bubbles indicates this change as it suggests that the reactants are combing to form products i.e. it signals a chemical reaction.
If a beaker is contained with the substances nickel sulfate, zinc sulfate and solid iron, there is a substance that will be reduced in the following substances that is in it. The substance that will be reduced as it is in the beaker is the Ni^2 + or also known as the Nickel (II)
Answer:

Explanation:
Hello!
In this case, since calcium's oxidation state when forming ionic bonds is +2 and sulfur's oxidation state when bonding those bonds is -2, for the required formula we write:

Now, since they have the same charge number, we infer the ionic compound formed when they bond is calcium sulfide:

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