Science, Tech, Math › Science What Is the Most Abundant Element? The Most Abundant Element in the Universe, the Earth, and the Human Body Share Flipboard Email Print Hydrogen and Oxygen are two of the most abundant elements. Rajvir Singh / Getty Images Science Chemistry Periodic Table Basics Chemical Laws Molecules Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated November 05, 2019 The most abundant element in the universe is hydrogen, which makes up about three-quarters of all matter! Helium makes up most of the remaining 25%. Oxygen is the third-most abundant element in the universe. All of the other elements are relatively rare. The chemical composition of Earth is quite a bit different from that of the universe. The most abundant element in the Earth's crust is oxygen, making up 46.6% of Earth's mass. Silicon is the second most abundant element (27.7%), followed by aluminum (8.1%), iron (5.0%), calcium (3.6%), sodium (2.8%), potassium (2.6%). and magnesium (2.1%). These eight elements account for approximately 98.5% of the total mass of the Earth's crust. Of course, the Earth's crust is only the outer portion of the Earth. Future research will tell us about the composition of the mantle and core. The most abundant element in the human body is oxygen, making up about 65% of the weight of each person. Carbon is the second-most abundant element, making up 18% of the body. Although you have more hydrogen atoms than any other type of element, the mass of a hydrogen atom is so much less than that of the other elements that its abundance comes in third at 10% by mass. Source "Element Distribution in the Earth's Crust"