An exciting time for chemistry
Two new elements, flerovium
Fl and livermoreium
Lv have been approved for entry in the Periodic Table of the Elements! They were formerly known by blander names—
ununhexium. In honor of the event, I assembled a gallery of periodic tables, but let me tell you more about the table first.
The chemical elements are arranged from top to bottom, in order of lowest to highest atomic number. (Atomic number is the same as the number of protons.) There are 118 elements. 98 are naturally occurring, and 14 occur naturally in decay chains of those 98, up to and including californium. The remaining six elements are lab synthesized.
Why is it periodic?
Table rows are “periods” and table columns are “groups.” Some groups have specific names, e.g. the noble gases, occupying the last column on the right. Some rows do too, such as the lanthanides and actinides on the bottom two rows.
The table is also periodic because its inventor, Dmitri Mendeleev, intended for it to be updated periodically, as new elements are found. So Mendeleev’s design had a dual use: for describing how the elements relate to each other, as well as for inferring the properties of new and not yet found elements.
One scientific concept to rebuild civilization
Here is a great quote from a recent LANL news story by David Hobart, Actinide Analytical Chemistry, History of the periodic table…and my history with it:
As the legendary physicist Richard Feynman put it, “If some universal catastrophe was to engulf the world and humankind could retain only one scientific concept to rebuild civilization, what would it be? The chemist’s answer is almost invariably the Periodic Table of the Elements.“