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

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?

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

Color Periodic Table with 118 Elements and Charges
This periodic table with charges is a useful way to keep track of the most common oxidation numbers for each element. Each element square contains all 118 of elements with the element number, symbol, name, atomic mass, and most common oxidation number. The different colors correspond to the different element […]

Periodic Table with Charges – 118 Elements

Trivalent and hexavalent chromium are the two common forms of the element. This is chromium(VI) oxide. (BXXXD)
Hexavalent chromium is a toxic metal you can be exposed to that can cause serious health effects. Here is what hexavalent chromium is, what it does, and how to protect yourself against it. Other Names for Hexavalent Chromium Hexavalent chromium is also known as Cr(VI), Cr-6, chromium-6, Hex Chrom, Hex […]

Hexavalent Chromium – What You Need to Know

Definitions of chemistry terms may be confusing. (chuttersnap)
Learn the difference between two important chemistry terms. Sometimes these words are (incorrectly) used interchangeably. Other times, they are the terms students have a hard time keeping straight. These are differences relating to chemistry and the physical sciences, although you’ll encounter some of these terms in daily life, too. What […]

Commonly Confused Chemistry Terms