The Periodic Table Explained

I post insecurely in front of the periodic table display  at the U of Iowa (featuring actual elements).
I pose insecurely in front of the periodic table display at the U of Iowa (featuring actual elements).

A while back a friend asked: what’s the deal with chemists and the periodic table? In a nutshell, the periodic table displays all of the elements in an order that allows chemists to know something about each one at a glance.

The elements are arranged by increasing atomic number–the number of protons (+ charges)–roughly equivalent to increasing weight. They are in rows according to the shell or as chemists would say, according to the quantum numbers. Quantum numbers are the equivalent to an element’s address and tell a lot about the electrons–negative charge cloud around the atom. Most of the time, reactivity is due to electrons and their placement around the atom. Conveniently, mother nature made it simple, as elements gain mass and electrons, they group themselves. The columns on the periodic table belong to elements growing ever larger but with the same arrangement of elections on the outside. This means, they react in similar fashion.

See that row on the right with the neon sign? Those are the noble gasses which don’t easily react with anything. Conversely, on the far left are things like sodium and potassium that react so easily to give elections that the elemental forms must be stored under an oil to keep them from joining up with oxygen. Why can you chose between chlorine and bromine for your hot tub? You’ll find chlorine above bromine on the table. They act much the same but chlorine is lighter.

Metals are on the left side along with hydrogen, the lightest element, and non-metals such as carbon, oxygen, and nitrogen are on the right. Elements in-between are the semi-metals or semiconductors. Radioactive elements, too big to be stable, have their weight in parenthesis.

This mortarboard, made by a clever Central College graduate, shows the system of symbols used for element names. The Cc abbreviation is for “Central College.” The numbers are for the proton number (the smaller number) and the weight of the element, which includes neutrons, heavy without charge.

Elemental mortarboard at Central College graduation.
Elemental mortarboard at Central College graduation.
I like to hand out periodic tables. If someone gives me a tract I will respond by giving them a table. I have even given periodic tables to children associated with the Westboro Baptist Church. I’ll give you one too. Just ask me. 🙂

There you have it. The periodic table will give up lots about the elements without requiring deep thought. The father of the Periodic Table was Mendeleev, a hairy dude who let his lust get the better of him and my guess is that this is why although he made the most useful tool ever imagined way back in 1869, he never got the Nobel Prize. He did it without knowing anything about the parts of the atom–the protons, neutrons, and electrons–basing it all on how each element reacted. That’s what science is all about, predicting, and what helped science slay the beast of fearful superstition that plagued humans throughout history.

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