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What's in this drink?

Chemistry Level 1

Fill in the blank with the correct element.

Water is composed of two hydrogen molecules and one ______ molecule.

Nitrogen Helium Phosphorous Oxygen

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Excel in math and science

Master concepts by solving fun, challenging problems.

It's hard to learn from lectures and videos

Learn more effectively through short, interactive explorations.

Used and loved by over 6 million people

Learn from a vibrant community of students and enthusiasts,
including olympiad champions, researchers, and professionals.

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That seems reasonable. Find out if you're right!

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by Rafaela L

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