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“As long as chemistry is studied, there will be a periodic table. And even if someday we communicate with another part of the universe, we can be sure that one thing both cultures will have in common is an ordered system of the elements that will be instantly recognizable by both intelligent life forms.” 

-John Emsley

What is the Periodic Table?

A structure for organizing chemical elements. The modern Periodic Table is arranged in order of atomic number.

K12 PTIf you have an iPad check out the FREE app "K12 Periodic Table"

Here are some other great online periodic table resources! Before you read up on the history and logic of the structure just click in and look around the Periodic Table.

Do we really need a Periodic Table?

Credit: AP Photo Eric RisbergWell, yes! We humans are great organizers: closets, sock drawers, play lists, tool boxes, athletic equipment. We sort, organize, and store things according to logical groupings because it makes things faster to find and easier to use. Imagine how long it would take you just to get dressed and out the door every day if all your stuff was just tossed around in random piles, or how long it would take you to find your favorite music if you had no way to create play lists or sort by song or artist. Time wasting mayhem.


The structure of the modern Periodic Table follows the Periodic Law. Elements are arranged from 1 to (currently) 116 based on atomic number (number of protons in the nucleus, remember?), which means groups or families of elements exhibit similar, predictable, physical and chemical properties. You'll learn all about that in the "Trends" section.

For now just trust me, if you are a chemist (and deep down there's a little chemist in all of us) you will grow to know and love your Periodic Table.

These resources will help you understand the basics of the Periodic Table:

A brief history of the modern Periodic Table

Although Dmitri Mendeleev is often credited as the "father" of the modern periodic table (it would still be my Cash Cab answer choice if asked) there were actually many scientists who contributed. You need to now these few key players:

In a nutshell as more and more elements were discovered, compared and analyzed, the need for way in which to organize them became increasingly important. The evolution of the modern Periodic Table makes sense if you think about it.

The very first Periodic Table, written by Antoine Lavoisier in the late 1700's, was basically a list of the then 33 elements grouped as metals or non-metals. In 1828 Jons Jakob Berzelius contributed the idea of atomic weights and added symbols. In 1829 John Doberiener introduced the idea of "triads" or groupings elements with similar properties. And so it went over the years with different scientists refining and adding to what is now a well organized tool that not only organizes existing elements but lets us predict the properties of new, as of yet undiscovered elements.

You need to focus on these two:

For you history buffs, these links give you an expanded history of our little friend:

How much do you need to know about the history of the Periodic Table?