Question

What is the most abundant element in the Earth's crust by weight percentage?

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

Hint:

Remember: \textbf{Oxygen + Silicon = Majority of crust}. Oxygen alone contributes nearly half of the Earth's crust.

Answer 1

The Correct Option is B

Concept: The Earth's crust is composed of various elements, but their abundance varies significantly. The composition is usually expressed in terms of weight percentage. The major elements in the Earth's crust are:

• Oxygen ($\sim$46.6%)
• Silicon ($\sim$27.7%)
• Aluminium ($\sim$8.1%)
• Iron ($\sim$5.0%)

Oxygen dominates because it forms oxides and silicate minerals, which make up the majority of crustal rocks. Step 1:Recall the abundance of elements in the crust.
Among all elements, oxygen has the highest percentage by weight.
Step 2:Compare with other options.
Although silicon is also abundant, it is significantly less than oxygen. Aluminium and iron occur in smaller proportions.
Step 3:Conclude the answer.
Thus, oxygen is the most abundant element in the Earth's crust.