Last of the Elements Discovered! Gotta catch 'em all!

Good news, citizens! In 1931, Science totally Pokemonned the very last of the elements, and the periodic table was totally full and stuff, because it now had eighty-five elements.

You just know that when you get all confident and print headlines like "Science Complete!" or "Last of the ELEMENTS Discovered", you're setting yourself up to look like a jerk in a couple years.

As of 2015, we know of 118 elements. The periodic table printed in this Popular Science Monthly shows 85, the most recent (at the time) discovery being "eka-iodine". So now, if you run and get out your t-shirt with the periodic table printed on it, you won't find eka-iodine on it. The name has changed a few times, we we learned more about the element. "Eka-iodine" just means "one space under iodine". That basically means "the thing that goes in the empty space under iodine", which isn't very descriptive. Since then, it's been called "albamine", "dakin", "helvetium", "anglo-helvetium", before the current record holder for longest-used-name-for-eka-iodine, "astatine". What's astatine good for? Since it's really radioactive, it's used in nuclear medicine. But don't eat it just because you feel a cold coming on.

The following elements just hadn't been discovered yet in 1931. In fact, they didn't even have empty spaces yet in their version of the table. They didn't even know these could exist yet. I think the discovery of these elements had everything to do with the advent of nuclear science.

• Neptunium
• Plutonium
• Americium
• Curium
• Berkelium
• Californium
• Einsteinium
• Fermium
• Mendelevium
• Nobelium
• Lawrencium

The following elements had their names changed, weirdly. This is probably because they change the names as they find out more about the elements. "Eka" is Sanskrit for "one", so any name with "eka" in it is probably just as temporary as "the thing under iodine". These elements had their names changed since then:

• niobium (columbium)
• astatine (eka-iodine)
• technetium (masurium)
• francium (ekacesium)
• protacinium (uranium x2)

So there you go. Next time you find some astatine lying around, try to put it in your thyroid, where it'll do you the most good, unless you don't have thyroid cancer. Top tip, there!

This periodic table has convenient little drawings to show you what the elements are good for. Print it out and put it on your fridge as a handy cheat sheet so you'll know what to do with any elements you may come across.

Gallium makes a nice soup

Hydrogen is good for building cylinders.

Neon is good to eat.

Nickel costs twice as much as it's worth.

Oxygen is dangerous, so use a gas mask.

Chlorine is just as dangerous as oxygen.

Potassium is filthy.

Scandium is good for making condoms.

Tantalum is always ten minutes late.

Uranium can't wait for Halloween.

Radon helps you sleep.