Yearly Archives: 2014

Tabla Periodica de los Elementos - BW — EDIT: This table has been updated to reflect corrections in the atomic weights of iron and gallium. The updated table can be found at Imprimible Tabla Periódica de los Elementos – Blanco y Negro 2015. This black and white printable periodic table is useful for those who need a Periodic Table in […]

Imprimible Tabla Periódica de los Elementos – Blanco y Negro

This entry was posted on September 28, 2014 by Todd Helmenstine (updated on June 21, 2021)

Diatomic Elements — A diatomic element is a molecule of an element consisting of two atoms. It is a form of homonuclear diatomic molecule. There are 7 diatomic elements, but only 5 diatomic elements at standard temperature and pressure (STP). The diatomic elements are hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, and iodine. List […]

What Are the 7 Diatomic Elements? Definition and List

This entry was posted on September 28, 2014 by Anne Helmenstine (updated on June 21, 2021)

Louis Pasteur — September 28 is Henri Moissan’s birthday. Moissan was the French chemist who was the first to successfully isolate the element fluorine. Isolating fluorine was a goal for many chemists throughout the 19th Century. It was known to be an element back in the late 18th century, but no one had […]

Today In Science History – September 28 – Henri Moissan ...

This entry was posted on September 27, 2014 by Todd Helmenstine (updated on November 12, 2025)

Scientific Method Steps — The scientific method is a system scientists and other people use to ask and answer questions about the natural world. In a nutshell, the scientific method works by making observations, asking a question or identifying a problem, and then designing and analyzing an experiment to test a prediction of what […]

Steps of the Scientific Method

This entry was posted on September 27, 2014 by Anne Helmenstine (updated on May 7, 2025)

Chemical and Physical Properties of Matter — Get examples of chemical and physical properties of matter.

Examples of Chemical and Physical Properties

This entry was posted on September 27, 2014 by Anne Helmenstine (updated on March 17, 2026)

FIRe IS FUN — There are thousands of words you can make using periodic table element symbols, so it makes sense there are many sentences you can write, too. Here’s what I have so far (it’s a work in progress). Clearly, I have a fascination with fire. Care to add your suggestions? FIRe IS […]

Sentences Made With Periodic Table Symbols

This entry was posted on September 27, 2014 by Anne Helmenstine (updated on May 17, 2015)

Sulfite Anion — Polyatomic ions are ions that contain more than one element. This polyatomic ions list contains many common ions, grouped by charge. Each entry contains the ion’s name, molecular formula and chemical structure. +1 Polyatomic Ions Ion Formula Structure Ammonium NH4+ Hydronium H3O+ -1 Polyatomic Ions Ion Formula Structure Acetate C2H3O2– […]

Polyatomic Ions List

This entry was posted on September 27, 2014 by Todd Helmenstine (updated on October 12, 2021)

Make Ectoplasm Slime for Halloween — Here's how to make ectoplasm slime for Halloween using water and edible fiber. It's so safe, it's even edible!

Make Ectoplasm Slime for Halloween

This entry was posted on September 27, 2014 by Anne Helmenstine (updated on November 2, 2024)

Dawn ignition — September 27 is Adolph Wilhelm Hermann Kolbe’s birthday. Kolbe was a German chemist who pioneered organic synthesis from inorganic sources. One of the synthesis reactions Kolbe is known for is the synthesis of salicylic acid. Salicylic acid is one of the main components in the manufacture of the most widely […]

Today In Science History – September 27 – Hermann Kolbe ...

This entry was posted on September 27, 2014 by Todd Helmenstine (updated on May 17, 2025)