hydrogen and oxygen
oxygen and water
Hydrogen and oxygen forming water molecules make up most of the ocean.
Ionized hydrogen and helium are the most abundant chemical elements in nebulae.
Hydrogen and helium are the most abundant elements in stars.
Hydrogen and oxygen are technically the most abundant elements, as they are the constituents of water (H2O). Excepting those two elements, chlorine, as chloride ions, is the most abundant element, followed by sodium ions.
Oxygen and silicon are the two most abundant elements in the Earth's crust. They make up about 75% of the Earth's crust by weight.
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The two most abundant elements in nebulae are hydrogen and helium. These elements make up the majority of the mass in interstellar clouds and are the building blocks for the formation of stars and planets.
Oxygen and silicon are the two most abundant elements found in the most common minerals. The most common minerals found on Earth are silicates.
The two most abundant element's in the earth's crust are oxygen and silicon. Refer to the related link to see a list of the most abundant elements in the earth's crust.
Hydrogen and Helium. :)
Hydrogen and oxygen