The Earth's crust, metal ores are present in the form of _________

The correct answer is oxides, sulphides and carbonates.

Key Points

• Metal ores in the Earth's crust are commonly found in the form of oxides, sulphides, and carbonates.
• Oxides include minerals like hematite (Fe₂O₃) and bauxite (Al₂O₃·2H₂O).
• Sulphides include minerals such as galena (PbS) and pyrite (FeS₂).
• Carbonates include minerals like calcite (CaCO₃) and dolomite (CaMg(CO₃)₂).
• These forms are the primary sources for extracting metals in various mining processes.

Additional Information

• Oxides: These are compounds of oxygen and metals. They are typically formed through the oxidation process.
• Sulphides: These are compounds of sulfur with metals. They are generally formed in reducing environments, like hydrothermal vents.
• Carbonates: These are salts of carbonic acid containing the carbonate ion (CO₃^2-). They are usually formed in sedimentary environments.
• Mining and Extraction: The process of obtaining metals from ores involves various techniques like smelting, electrolysis, and chemical reduction.
• Economic Importance: The extraction of metals from these ores is crucial for various industries including construction, electronics, and manufacturing.