Elements

Elements are the smallest units of matter that can’t be divided using chemical means. They are the building blocks of matter. Learn the names of the elements and get facts about them.

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

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

Tabela Periódica Portuguesa — This table is a list of the elements in English and Portuguese arranged by atomic number.

List of Elements in Portuguese

This entry was posted on October 28, 2019 by Todd Helmenstine (updated on October 28, 2019)

Periodic Table of Radioactive Elements — Technetium is a radioactive element, with no stable isotopes. With an atomic number of 43, it is the lightest unstable element. All of the elements surrounding it on the periodic table have at least one stable isotope. What is it about technetium that makes it special? The short answer is […]

Why Is Technetium Radioactive?

This entry was posted on September 12, 2019 by Anne Helmenstine (updated on November 1, 2019)

Periodic Table of Radioactive Elements — This is a list of the radioactive elements of the periodic table. While all elements have some radioactive isotopes, these 37 elements have no stable isotopes. These elements are considered the "radioactive elements".

What Are the Radioactive Elements?

This entry was posted on September 9, 2019 by Todd Helmenstine (updated on September 15, 2019)

CPK-Jmol Periodic Table — Chemistry departments often have kits of plastic balls to stick together to represent atoms and their arrangement in molecules. These kits come with several different colors to easily distinguish one element from another. The choice of color for each atom is not arbitrary. The color code of these atoms is known as CPK colors.

Molecule Atom Colors – CPK Colors

This entry was posted on August 28, 2019 by Todd Helmenstine (updated on December 3, 2019)

These are the transition metals, according to the IUPAC definition. — The transition metals are the largest group of elements on the periodic table. They got their name because English chemist Charles Bury described a transition series of elements in 1921. Bury examined the transition from an inner electron layer with 8 electrons to a layer with 18 electrons and from […]

Transition Metals Definition, List and Properties

This entry was posted on January 29, 2019 by Anne Helmenstine (updated on March 1, 2020)