Nitrogen finally joins the elite tier of elements like carbon that can form neutral allotropes—different structural forms of a single chemical element ... the main ingredients being chlorine (Cl 2) or ...

Bromine was first identified as a chemical element in 1826 by French chemist Antoine Balard. He isolated it from chlorine and found that, in its elemental form, bromine is a highly volatile, ...

Our Concept of the Chemical Element Modified by Study of Radio-Active Change. Skip to main content. Scientific American. August 2, 1919. 5 min read. What is a Chemical Element?

Each element is distinguished by the number of protons, neutrons and electrons that it possesses. The atoms of each chemical element have a defining and same number of protons and electrons, but – ...

On 17 February 1869, Russian chemist Dmitri Mendeleev jotted down the symbols for the chemical elements, putting them in order according to their atomic weights and inventing the periodic table .