Answer:
The correct option is;
It is always necessary to include a Roman numeral after the symbol of the metal
Explanation:
The transition metals can form ionic compounds with other elements by giving different number of electrons such that the transition metals can combine to form compounds in which they have different oxidation states
Therefore, in a compound formed by a transition metal, the value of the transition metal's valency or oxidation state in the compound is indicated by the inclusion of an equivalent Roman numeral after the transition metal in the name of the chemical formula of the compound
Maybe it's [Acid] and [H+ ions]
Acid Rain is a result of chemical compounds, like sulfur dioxide and nitrogen oxide, are released into the air. These compounds rise high into the atmosphere and react with the different elements and compounds in the air, such as oxygen and water. This reaction forms acidic pollutants and eventually fall back to the ground as acid rain. This phenomenon is attributed to industrial waste; and it was especially common in the wake of the Industrialization Era of the United States.
