Periodic table's seventh row finally filled as four new elements are added

theguardian ^ | 01/03/2016

[dhs12345]

Clever. :)

Just realized the obvious that few of the elements exist in their “elemental” state. So most of the table is derived the same way — theory and then experiment.

[day10]

Well done!

[DaxtonBrown]

“I found it very informative and entertaining.”

I believe it was elemental.

[Paladin2]

Nice.

Physicists need to study the imaginary plane of Electrical Engineers. Some stuff could be caught in those stringy mathematical thingeys too.

[Paladin2]

Can Wolfram be kilt with a wooden stake?

[FredZarguna]

The ever-prepared Batman always wins because he wears bright yellow underwear, anticipating just such a contretemps.

[FredZarguna]

The heavier elements that made their way into the Earth's crust certainly came from supernovas. Most of the very heavy radioactive products of nuclear reactions (which all the transuranium elements are) are seen naturally in uranium, because uranium isotopes are the endpoints of several decay chains, and are very stable. [²³⁵U has a half-life of >700 million years, ²³⁸U 4.5 billion years.]

Actually seeing the very heavy elements, however fleetingly, in a lab is important. If you look at this chart the number of protons (Z) goes down the right hand diagonal, while the number of neutrons (n) goes down the left hand diagonal. The most stable isotopes are in the center of the chart as you move diagonally. What you will notice is that for the lighter elements, the number of protons and neutrons is roughly the same (¹²C has six of each, oxygen's most stable isotope has eight of each.) But as you go further down the chart, you discover that the heavier an atom gets, the more the number of neutrons increases relative to the number of protons.

The reason for this is that the protons and neutrons are attracted to each other via the strong nuclear force, but protons also tend to repel each other because of their electric charge. To balance the strong force against the electromagnetic force, the electrically neutral neutrons provide a "screening" effect where they shield the protons from each other. This effect requires more and more neutrons to keep the nucleus stable as the number of protons increases.

With this simple model, maybe elements of arbitrarily large atomic mass can exist. But maybe they can't. We do not know the orbital structure of nucleons anywhere near as completely as we know the orbital structure to be for electrons [for Hydrogen, electronic orbital configuration is an exactly solvable problem, and for heavier elements it's a multibody force problem, which can't be solved in closed form, but the computer models are very good --for electrons.] Because of this, it's quite possible that nature might reach a point where no amount of neutron shielding can keep the protons close enough together to keep an atomic nucleus stable.

[minnesota_bound]

Wait till they get to element 199!!
Star travel, time travel, portals. Can’t wait : )

[Ozark Tom]

Includes a dark matter component explaining Krypton’s high gravitation and density?

[Do the math]

With the creation Bose�€“Einstein condensate several years ago, it proved Einstein's conjecture that it is possible to create an atom with a huge atomic number. The search continues.

[roadcat]

Like other superheavy elements that populate the end of the periodic table, they only exist for fractions of a second before decaying into other elements.

I've read theories that the eighth row may contain superheavy elements that are stable. When they are discovered, it will herald a wondrous era of discovery for humankind. I'm hoping it happens within my lifetime.