About 50% of the Earth's crust, including the waters on the Earth and atmosphere, is?

  • A. Oxygen
  • B. Cabon Dioxide
  • C. Silicon
  • D. Clay

Explanation

Oxygen forms about 46% of the Earth's crust by mass, making it the most abundant crustal element. The figure is often rounded to about 50%, while carbon dioxide and clay are not elemental components in this sense.

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