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What chemical element is the majority of Earth’s atmosphere composed of?

  1. Helium

  2. Oxygen

  3. Carbon

  4. Nitrogen

The correct answer is: Nitrogen

The majority of Earth's atmosphere is composed of nitrogen. This can be seen by looking at the periodic table and seeing that nitrogen (N) has an atomic number of 7, making it the 7th most abundant element in the atmosphere. Helium and carbon are both noble gases and make up a very small percentage of the atmosphere. Oxygen is the 2nd most abundant element in the atmosphere, but still does not make up the majority. Therefore, the correct answer is D Nitrogen.