Question

Which element constitutes the largest percentage of the Earth's crust?

• A. Silicon
• B. Aluminium
• C. Oxygen
• D. Iron

Answer 1

Answer:

C. Oxygen

Composition of the Earth's Crust

• The Earth's crust, the outermost solid shell of the planet, is primarily composed of elements derived from the process of planetary differentiation.
• Oxygen is the most abundant element, making up approximately 46.6% by weight of the Earth's crust. It is mainly found bonded with other elements in silicate minerals.
• Silicon is the second most abundant element, constituting about 27.7%. It is a key component of silicate minerals, which form the bulk of the crust.
• Other significant elements include:
  • Aluminum: Around 8.1%
  • Iron: Approximately 5.0%
  • Calcium: About 3.6%
  • Sodium: Roughly 2.8%
  • Potassium: Approximately 2.6%
  • Magnesium: About 2.1%
• These elements combine to form a vast array of rocks and minerals, with silicates (minerals containing silicon and oxygen) being the most common group, representing over 90% of the Earth's crust.
• The abundance of oxygen is due to its high reactivity and its role in forming oxides and silicates.