<span>Si is reduced/Oxidizing reagent Mg is oxidized/reducing reagent</span>
The 1st law of thermodynamics doesn't specify that matter can be created nor destroyed, but that the total amount of energy in a closed system cannot be created nor destroyed though it can be changed from one form to another.
The answer is c because it is helpful to understand the balance between these two ions. An aqueous solution is a solution in which water is the solvent. Water molecules (H2O) are polar, meaning that they have a negative end (the oxygen) and a positive end (the hydrogens). When there is a reaction in an aqueous solution, the water molecules have the ability to attract and temporarily hold a donated proton (H+). This creates the hydronium ion (H3O+).
Hydrogen sulfide is a <u>compound</u>
<h3>Explanation</h3>
A compound is a substance composed of two or more element in a fixed proportion and it can be separated into simpler substance and element only by chemical method. Hydrogen sulfide is a chemical compound with H2S formula.