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Explanation:

The Stock System states that In a chemical formula or equation, some metals need a roman numeral after their symbol. If a metal has multiple oxidation states, it needs a roman numeral.

Use the Periodic Table to see the oxidation states for each metal.

We can see that cobalt, iron, and copper have more than one oxidation state, so they would require a roman numeral.

state the principle of separating two immiscible liquids by separating funnel. describe an activity with diagram to separate a mixture of water and kerosene oil. answer: immiscible layers separate out in layers depending on their densities in separating funne