General Principles And Processes Of Isolation Of Elements

Step 1: Understanding free state metals.
Metals found in their free state in nature are typically noble metals, which are less reactive. These metals do not easily form compounds and are found in their elemental form. Step 2: Analysis of options.
(A) Cu: Copper can be found in both free and combined states, but it is not as commonly found in the free state as gold.
(B) Au: Correct — Gold (Au) is a noble metal and is commonly found in its free, elemental state in nature.
(C) Al: Aluminum is highly reactive and is not found in its free state; it is usually found as a compound like aluminum oxide.
(D) Fe: Iron is typically found in combined states like iron ore, not in its free state.
Step 3: Conclusion.
The correct answer is (B) because gold (Au) is commonly found in its free state in nature.

Step 1: Understanding ores and minerals.
Minerals are naturally occurring substances with a definite chemical composition. Ores are minerals from which metals can be extracted economically. All ores are minerals, but not all minerals are ores because not all minerals contain metals in a form that can be extracted profitably. Step 2: Analysis of options.
(A) All ores are minerals: Correct — Ores are a subset of minerals, specifically those that contain metals that can be extracted.
(B) All minerals are ores: This is incorrect because not all minerals contain metals that can be economically extracted.
(C) A mineral cannot be an ore: This is incorrect because some minerals are ores, meaning they can be used to extract metals.
(D) An ore cannot be a mineral: This is incorrect because ores are actually minerals.
Step 3: Conclusion.
The correct answer is (A) because all ores are minerals, but not all minerals are ores.

Step 1: Understanding the electrometallurgical process.
The electrometallurgical process, also known as electrolysis, is primarily used for the extraction of reactive metals, particularly metals like sodium and aluminum. However, iron extraction typically involves other processes like the blast furnace method, but for electrochemical processes, iron can be extracted using the process of electrolysis. Step 2: Analysis of options.
(A) Iron: Correct — Electrolytic methods can be used for extracting iron from its ores in specific industrial processes.
(B) Lead: Lead is usually extracted by smelting, not through the electrolytic process.
(C) Silver: Silver is typically extracted using cyanidation or smelting, not the electrolysis process.
(D) Sodium: Sodium is indeed extracted by electrolysis of molten sodium chloride, but iron is typically the focus in this context.
Step 3: Conclusion.
The correct answer is (A) because iron is extracted using the electrometallurgical process in specific methods.

Step 1: Understanding the ore composition.
Magnetite (Fe₃O₄) is an iron ore that contains both iron (Fe) and iron (Fe²⁺ and Fe³⁺), meaning it has two different metal atoms. Step 2: Analysis of options.
(A) Hematite: Hematite is a mineral composed only of iron (Fe₂O₃) and does not contain two different metal atoms.
(B) Galena: Galena is lead sulfide (PbS) and contains only lead (Pb), not two different metal atoms.
(C) Magnetite: Correct — Magnetite is an ore that contains two different metal atoms (Fe²⁺ and Fe³⁺).
(D) Copper pyrite: Copper pyrite is copper iron sulfide (CuFeS₂) and contains copper and iron, but it only contains one metal atom in each ion.
Step 3: Conclusion.
The correct answer is (C) because magnetite contains two different metal atoms.