Science, Tech, Math › Science What Is the Sun Made Of? Table of Element Composition Learn About Solar Chemistry Share Flipboard Email Print The sun consists mostly of hydrogen and helium. SCIEPRO/ Brand X Pictures/ Getty Images Science Chemistry Chemical Laws Basics Molecules Periodic Table 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. 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. Updated January 12, 2018 You may know the Sun consists mainly of hydrogen and helium. Have you ever wondered what about the other elements in the Sun? About 67 chemical elements have been detected in the sun. I'm sure you're not surprised that hydrogen is the most abundant element, accounting for over 90% of the atoms and over 70% of solar mass. The next most abundant element is helium, which accounts for almost just under 9% of the atoms and about 27% of the mass. There are only trace amounts of other elements, including oxygen, carbon, nitrogen, silicon, magnesium, neon, iron, and sulfur. These trace elements make up less than 0.1 percent of the mass of the Sun. Solar Structure and Composition The Sun is constantly fusing hydrogen into helium, but don't expect the ratio of hydrogen to helium to change anytime soon. The Sun is 4.5 billion years old and has converted about half of the hydrogen in its core into helium. It still has about 5 billion years before the hydrogen runs out. Meanwhile, elements heavier than helium form in the Sun's core. They form in the convection zone, which is the outermost layer of the solar interior. Temperatures in this region are cool enough that the atoms have enough energy to hold their electrons. This makes the convection zone darker or more opaque, trapping heat and causing the plasma appear to boil from convection. The motion carries heat to the bottom layer of the solar atmosphere, the photosphere. Energy in the photosphere is released as light, which travels through the solar atmosphere (the chromosphere and corona) and passes into space. Light reaches the Earth about 8 minutes after it leaves the Sun. Elemental Composition of the Sun Here is a table listing the Sun's elemental composition, which we know from analysis of its spectral signature. Although the spectrum we can analyze comes from the solar photosphere and chromosphere, scientists believe it is representative of the whole Sun, except for the solar core. Element % of total atoms % of total mass Hydrogen 91.2 71.0 Helium 8.7 27.1 Oxygen 0.078 0.97 Carbon 0.043 0.40 Nitrogen 0.0088 0.096 Silicon 0.0045 0.099 Magnesium 0.0038 0.076 Neon 0.0035 0.058 Iron 0.030 0.014 Sulfur 0.015 0.040 Source: NASA - Goddard Space Flight Center If you consult other sources, you'll see the percentage values vary by up to 2% for hydrogen and helium. We can't visit the Sun to sample it directly, and even if we could, scientists would still need to estimate the concentration of elements in other portions of the star. These values are estimates based on the relative intensity of spectral lines. Continue Reading What Is the Universe Made Of? The Story of Our Star: 10 Things You Should Know About the Sun Life on the Main Sequence: How Stars Evolve Sun Facts: What You Need to Know Tales from the Primordial Solar System Digging Into the Interstellar Medium Get Facts About the Element Helium What Happens to Aging Stars Like the Sun Going Inside a Star to See How It Works How Stars Make All of the Elements What is the Universe Made Of? The Woman Who Explained the Sun and Stars Get Facts About the Element Chlorine Get Facts About the Element Oxygen The Exosphere Is a Strange and Wondrous Place What Do the Numbers on the Periodic Table Mean?