Anne Helmenstine

Strong and Weak Acids — Strong and weak acids are key concepts in chemistry. Strong acids completely dissociate into their ions in water, while weak acids incompletely dissociate. There are only a few strong acids, but many weak acids. Strong Acids Strong acids completely dissociate in water into their ions and produce one of more […]

List of Common Strong and Weak Acids Recently updated !

This entry was posted on February 28, 2020 by Anne Helmenstine (updated on February 28, 2020)

Test Tubes of Blue Liquid — The blue bottle reaction is a classic color change chemistry demonstration. It interests students in chemistry, introduces the scientific method, and illustrates oxidation and reduction (redox reactions) and chemical kinetics. The reaction starts as a blue liquid which becomes colorless and returns to its blue color. Materials The usual materials […]

Blue Bottle Chemistry Demonstration Recently updated !

This entry was posted on February 27, 2020 by Anne Helmenstine (updated on February 27, 2020)

Here are the names, element symbols, and atomic numbers of the first 20 elements of the periodic table. — It’s handy to know the first 20 elements of the periodic table. Around 99% of the mass of the human body is made of six of these elements. The first 20 elements are also a good overview of the different element groups. The elements are listed in order of increasing […]

First 20 Elements of the Periodic Table Recently updated !

This entry was posted on February 26, 2020 by Anne Helmenstine (updated on February 26, 2020)

Gatorade and drain cleaner color change — The Gatorade and drain cleaner color change chemistry demonstration is a variant of the classic blue bottle demo. You can customize the demo to get a range of colors. The best part is you don’t need access to a chemistry lab for the materials, so this is a great project […]

Gatorade and Drain Cleaner Color Change Chem Demo Recently updated !

This entry was posted on February 25, 2020 by Anne Helmenstine (updated on February 28, 2020)

Glowing Flowers — Flowers are already beautiful, but have you ever wanted to make glowing flowers so you could see them in the dark? All you need is a bit of basic chemistry and biology to make real flowers glow. Here are four methods to make glowing flowers. There are instructions for both […]

How to Make Glowing Flowers Recently updated !

This entry was posted on February 24, 2020 by Anne Helmenstine (updated on February 24, 2020)

Hot and Cold Volcanoes — Learn about endothermic and exothermic reactions by making cold and hot chemical volcanoes. This project is more entertaining than mixing chemicals in beakers and measuring their temperatures. The volcanoes use common, safe household ingredients. Endothermic and Exothermic Reactions An endothermic chemical reaction absorbs energy from its environment, so the reaction […]

Hot and Cold Volcano: Easy Endothermic and Exothermic Reactions Recently updated !

This entry was posted on February 23, 2020 by Anne Helmenstine (updated on February 23, 2020)