Chemistry

Learn about chemistry, the study of matter and its reactions. Find projects, study notes, periodic tables, and worked example problems.

Elements found in nature — There are 118 elements on the periodic table, but how many of these elements can be found in nature? Some of the elements on the periodic table are strictly man-made and do not exist in nature. A few elements exist naturally but are found only in trace amounts. This table […]

What are the Naturally Occurring Elements? – Elements Found In ... Recently updated !

This entry was posted on June 12, 2018 by Todd Helmenstine (updated on June 14, 2018)

Abundance of Elements Earth Crust Periodic Table — Earth’s crust contains nearly all of the naturally occurring elements. This table and periodic table shows the relative abundance of elements in the Earth’s crust. Each element is represented by its atomic number, symbol, name, and abundance in milligrams per kilogram of Earth’s crust. Since 1 milligram is one-millionth of […]

Abundance of Elements in Earth’s Crust – Periodic Table and ...

This entry was posted on May 23, 2018 by Todd Helmenstine

Seawater Element Abundance — Earth’s oceans cover 71% of the surface of the planet. Even a casual inspection will tell you there is more to seawater than just water. You would expect the two most common elements to be water itself, hydrogen and oxygen. What else is found in Earth’s oceans? These tables answer […]

Abundance of Elements in Earth’s Oceans – Periodic Table and ...

This entry was posted on May 20, 2018 by Todd Helmenstine (updated on May 26, 2018)

Silicone is a polymer, like this blue cup. Silicon is a metalloid element. (Tatsuo Yamashita) — Silicon and silicone are two commonly confused terms. It’s understandable, since the only difference between the written words is the letter “e.” However, one is an element from the periodic table, while the other is a compound that contains that element. They aren’t the same, any more than saying carbon […]

What Is the Difference Between Silicon and Silicone?

This entry was posted on April 4, 2018 by Anne Helmenstine

Glow in the dark crystals are brightest if the crystals are clear rather than colored. — If you think regular crystals are boring, try growing glow in the dark crystals. These magical creations are easy to make, but you need to apply a bit of science to get them to work. Why Glow in the Dark Crystal Kits Don’t Work If you’ve purchased glow in the […]

How to Grow Glow in the Dark Crystals

This entry was posted on March 28, 2018 by Anne Helmenstine (updated on April 9, 2018)

The use of petrochemicals in medicine includes the manufacture of pills, capsules, and disposable syringes. — It’s hard to notice what’s going on around you when you’re injured or sick. You may be surprised at the key role played by petrochemicals in medicine. Some uses are obvious, like plastic tubes and containers. Most uses of petroleum are much harder to see. Petroleum products save doctors and […]

Petrochemicals in Medicine

This entry was posted on February 21, 2018 by Anne Helmenstine (updated on February 27, 2018)