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

The Earth's crust is the outermost solid shell of the planet. While it contains many elements, a few make up the vast majority of its mass. The abundance is typically measured as a percentage of the total weight.
Step 1: Understanding the Question:
The question asks to identify the single element that constitutes the largest portion of the Earth's crust by weight.
Step 2: Detailed Explanation:
Let's look at the approximate weight percentages of the most common elements in the Earth's crust:

Oxygen (O): \(\sim\) 46.6%

Silicon (Si): \(\sim\) 27.7%

Aluminium (Al): \(\sim\) 8.1%

Iron (Fe): \(\sim\) 5.0%

Calcium (Ca): \(\sim\) 3.6%

Sodium (Na): \(\sim\) 2.8%

Potassium (K): \(\sim\) 2.6%

Magnesium (Mg): \(\sim\) 2.1%

Oxygen is by far the most abundant element. This is because it is the primary component of silicate minerals (\(SiO_4\)), which are the building blocks of most crustal rocks, and it also forms oxides with other elements.
Step 3: Final Answer:
By weight percentage, Oxygen is the most abundant element in the Earth's crust.