The periods of the periodic table are determined by patterns in the electronic structure which lead to periodic patterns in the properties of elements.

The first period contains 2, then 8, 8, 18, 18, 32, 32 … repeated pairs of square numbers times two.

A long form periodic table looks like this:

32 column table

Period 1 contains only H and He. Periods 2 and 3 contain s-fillers and p-fillers: The old Groups 0, I, II, etc up to VII.

Periods 4 and 5 also contains d-transition elements.

Periods 6 and 7, in addition to the above, contain f-block elements. These are lanthanides and actinides.

You’ll see that in this table, lutetium is not included as a lanthanide: quite often, it is considered a lanthanide because of its similarity with the (other) lanthanides, but it is also a d-block element, whereas the other lanthanides are f-block elements. Similarly, this chart shows lawrencium as excluded from the actinides: often, it is considered an actinide, but it is a d-block, not an f-block.

Because this is a very long table, a short form is usually included in books with only 18 columns.

Sometimes there is a gap of two squares in the third column, with a note or arrow pointing to the actinides and lanthanides, including lawrencium and lutetium.

Gap for Actinides and Lanthanides

Then you get this kind, with actinium and lanthanum in the third column

I think that is the worst: actinium and lanthanum are not much like scandium and yttrium.

I prefer this kind:
http://www.meta-synthesis.com/webbook/35_pt/we2.png

This has all the d-block elements together in a box, and the f-block elements somewhere else in a box.

dv said:

The periods of the periodic table are determined by patterns in the electronic structure which lead to periodic patterns in the properties of elements.

Now slow down egghead!

dv said:

A long form periodic table looks like this:

This is how my brane pictures the periodic table, but unfortunately for me, none of my text books have ever used it, or even mentioned it as an option and when I asked my chem teacher about it, she wasn’t sure… IIRC I created it myself for fun one day.

dv said:

I prefer this kind:
http://www.meta-synthesis.com/webbook/35_pt/we2.png

This has all the d-block elements together in a box, and the f-block elements somewhere else in a box.

Acceptable and suitable for the masses.

Hopefully no one will synthesise anything past ununoctium during our life times because adding the 18 column g-block would be ungainly.

Hopefully no one will synthesise anything past ununoctium during our life times because adding the 18 column g-block would be ungainly.

I’m not optimistic.

OCDC said:

I’m not optimistic.

IKR

dv said:

Hopefully no one will synthesise anything past ununoctium during our life times because adding the 18 column g-block would be ungainly.

I’m hoping we get to create something from the lower end of the theoretical second island of stability. It’ll be an ultra-heavy element of course.

I thought you’ld like something like this:
http://www.meta-synthesis.com/webbook/35_pt/pt_database.php?PT_id=535

Not exactly suitable for printing in a textbook.

dv said:

I eagerly await Tom Lehrer’s song “The New Period Table”.

That spiral might look good but it contains no useful information…

dv said:

!http://www.chartgeek.com/wp-content/uploads/2012/09/alternative-periodic-table1.png

That’s good.

:)

furious said:

That spiral might look good but it contains no useful information…

Seems harsh. It places elements in their groups and periods and, unlike a traditional table, shows that the sequence just continues without breaks.

• Seems harsh. It places elements in their groups and periods and, unlike a traditional table, shows that the sequence just continues without breaks.

My mouse pad contains the traditional table, its not fancy but it does the job and is very useful…

I’m not saying that spiral one is likely to replace the traditional number. For one thing, it is not space efficient.

Not exactly suitable for printing in a textbook.

I was going to suggest one of those spirally ones but I thought precisely that that one was better for standard printing.

• I’m not saying that spiral one is likely to replace the traditional number. For one thing, it is not space efficient.

As an illustrative tool it would be handy, look good on a shirt…

Inspired by that swirly version, I did up this one for my daughter.

The basic eight groups are in a helix while he d-block and f-block are out in separate loops.

I think this is better than a normal flat periodic table in that:
a) all the elements from 1 to 118 can be traced consecutively without break
b) or alternatively you can just trace through the basic eight groups round and round
c) the big gaps are removed: boron is shown adjacent to beryllium. Sodium is shown adjacent to neon for example: to my mind this makes sense because the sodium ion is isoelectronic with neon.

Meanwhile it still retains the traditional organisation into groups. I’ve kind of left H sticking out from the rest because it is such an oddball.

I made it by first putting the elements into a strip from 1 to 118 and then folding and sticking it into place with tape but I now think that is unnecessarily complicated. Probably better to just print the basic eight, the d-block and the f-block as separate rectangles, with little “fold and paste” tabs.

Well done.

Just stick the 36 ones you love most onto a Rubric cube but you can only have on Zn.
Then you can pull it out, the cube that is, at airports and bus stations and play wit it.

Bubblecar said:

Well done.

Thank you

Peak Warming Man said:

Just stick the 36 ones you love most onto a Rubric cube but you can only have on Zn.
Then you can pull it out, the cube that is, at airports and bus stations and play wit it.

Hold the phone surely there are 54 squares on such a cube?

Not a periodic table but interesting, schematic of relationships in the Syrian civil war.

dv said:

Peak Warming Man said:

Just stick the 36 ones you love most onto a Rubric cube but you can only have on Zn.
Then you can pull it out, the cube that is, at airports and bus stations and play wit it.

Hold the phone surely there are 54 squares on such a cube?

Yes I think your right six faces with nine squares with the periodic table element symbols on each square.
I was thinking six squares there for a while.

What, support from Assad to Isis is alleged? That’s weird.

Peak Warming Man said:

dv said:

Peak Warming Man said:

Just stick the 36 ones you love most onto a Rubric cube but you can only have on Zn.
Then you can pull it out, the cube that is, at airports and bus stations and play wit it.

Hold the phone surely there are 54 squares on such a cube?

Yes I think your right six faces with nine squares with the periodic table element symbols on each square.
I was thinking six squares there for a while.

Okay well if I think I can pare it down to 54 elements, I mean who GAF about dud elements like rhodium and lutetium?

And Americium and Tasmanium, plus I’d lose the halogens, a more nasty group of wastrel elements you’ll never find.

Peak Warming Man said:

And Americium and Tasmanium, plus I’d lose the halogens, a more nasty group of wastrel elements you’ll never find.

Chlorine is essential for human life, fluorine also plays an important health role. You can scratch bromine and iodine but I will be putting forward a submission to keep Cl and F on board.

Well hush my grits, turns out I and Br are also needed.

Every stable and long half-life element is found in the human body, but most are either “inactive” or actually bad news.

Only the following elements have been proven to be required for human health:

O, C, H, N, Ca, P, K, S, Cl, Mg, Fe, Zn, F, Cu, I, Se, Ni, Mn, Mo, Co.

Si, Sr, Rb, Br, B, Cr, As, Li, V may also be required.

The rarest element by human body composition that is required by humans is cobalt, which makes up about 20 parts per billion.

The commonest that is probably NOT required is rubidium, about five parts per million.

dv said:

Well hush my grits, turns out I and Br are also needed.

Every stable and long half-life element is found in the human body, but most are either “inactive” or actually bad news.

Only the following elements have been proven to be required for human health:

O, C, H, N, Ca, P, K, S, Cl, Mg, Fe, Zn, F, Cu, I, Se, Ni, Mn, Mo, Co.

Si, Sr, Rb, Br, B, Cr, As, Li, V may also be required.

The rarest element by human body composition that is required by humans is cobalt, which makes up about 20 parts per billion.

The commonest that is probably NOT required is rubidium, about five parts per million.

Well I hope that doesn’t get out.

CORNFLAKES – NOW WITH ADDED COBALT FOR A STRONGER BLUER COMPLEXION

Peak Warming Man said:

dv said:

Well hush my grits, turns out I and Br are also needed.

Every stable and long half-life element is found in the human body, but most are either “inactive” or actually bad news.

Only the following elements have been proven to be required for human health:

O, C, H, N, Ca, P, K, S, Cl, Mg, Fe, Zn, F, Cu, I, Se, Ni, Mn, Mo, Co.

Si, Sr, Rb, Br, B, Cr, As, Li, V may also be required.

The rarest element by human body composition that is required by humans is cobalt, which makes up about 20 parts per billion.

The commonest that is probably NOT required is rubidium, about five parts per million.

Well I hope that doesn’t get out.

CORNFLAKES – NOW WITH ADDED COBALT FOR A STRONGER BLUER COMPLEXION

How the hell did you get ‘CORNFLAKES’ out of O, C, H, N, Ca, P, K, S, Cl, Mg, Fe, Zn, F, Cu, I, Se, Ni, Mn, Mo, Co.???

The closest iget is
CoZnFIKSe…

>The rarest element by human body composition that is required by humans is cobalt, which makes up about 20 parts per billion.

I thought it was iodine.

Bubblecar said:

>The rarest element by human body composition that is required by humans is cobalt, which makes up about 20 parts per billion.

I thought it was iodine.

No, that was the rarest element (required by humans) by cosmic abundance or suchlike.

Bubblecar said:

Bubblecar said:

>The rarest element by human body composition that is required by humans is cobalt, which makes up about 20 parts per billion.

I thought it was iodine.

No, that was the rarest element (required by humans) by cosmic abundance or suchlike.

yes

“The rarest element by human body composition that is required by humans is cobalt, which makes up about 20 parts per billion.

The commonest that is probably NOT required is rubidium, about five parts per million.”

Stylin’ factoids.

Oh one does one’s humble best.

Further to this, I manufactured a set of ion sticks to help my daughter study stoichiometry.

I used a sheet of 3 mm cardboard, a ruler, pencil, couple of sticks of glue, and a colour printer. There are 116 sticks, double sided. I have at least three of each ion, except for the trivalent ions, of which I have at least two. The labels are colour-coded to divide the ions into broad categories: d-transition metal cations, alkali metal cations, alkali earth metal cations, polyatomic cations, post-transition metal cations, halides, other simple anions, inorganic molecular anions, organic anions. H+ and H- I gave their own colours, as they are really quite different from any other category.

Cations have triangular tabs, one for each valence electron.
Anions correspondingly have triangular divots.

This enables the user to snap cations and anions together in appropriate ratios. Here, strontium arsenite is shown.

The sticks are 2.5 cm wide, and have a length of 5 cm per valence electron.

Could probably be improved by giving the divots a stronger barrier on the front and back, we are finding the anions are crinkling a bit after repeated use.

Probably even better if made of wood but I would need a shed for that.

The last federal election was held on 7 September 2013, and the 44th Parliament of Australia opened on 12 November 2013. The first date that a normal House and half-Senate election can be held is 6 August 2016. The last date on which the next election can be held is 14 January 2017, which is calculated in the following way:
http://en.wikipedia.org/wiki/Next_Australian_federal_election

this place is going to be fucked by the time the liberals are done with it

I’m most likely going to sell up and put my money overseas

I don’t see the relevance.

dv said:

I don’t see the relevance.

see chat

Politicians contain elements.

Did you know elephants are mostly made of four elements?

Yes.

Ppl talk about the basic four but are there actually any living things without P and S?

Ppl talk about the basic four but are there actually any living things without P and S?

Ppl talk about the basic four but are there actually any living things without P and S?

AFAIK re: P – no (I bring to your attention ATP)

re: S – uncertain (I bring to your attention its presence in some amino acids)

I suppose P would be a better bet than S in terms of true universality.

Phil says “Calcium is essential for living organisms, in particular in cell physiology, where movement of the calcium ion Ca2+ into and out of the cytoplasm functions as a signal for many cellular processes. “

So that might mean 7 core elements.

It’s a second messenger but I’m not sure if it’s essential in all prokaryotes.

OCDC said:

It’s a second messenger but I’m not sure if it’s essential in all prokaryotes.

What do you mean by “second messenger”?

dv said:

OCDC said:

It’s a second messenger but I’m not sure if it’s essential in all prokaryotes.

What do you mean by “second messenger”?

It’s not the first.

dv said:

OCDC said:

It’s a second messenger but I’m not sure if it’s essential in all prokaryotes.

What do you mean by “second messenger”?

Part of intracellular signal transduction pathways. I’m not sure if these are the same in pro- and eukaryotes.

dv said:

Further to this, I manufactured a set of ion sticks to help my daughter study stoichiometry.

How old is this poor daughter of yours?

Witty Rejoinder said:

dv said:

Further to this, I manufactured a set of ion sticks to help my daughter study stoichiometry.

How old is this poor daughter of yours?

17 months.

Well if you don’t know and I don’t know then we’ll have to check with MZL.

OCDC said:

Witty Rejoinder said:

dv said:

Further to this, I manufactured a set of ion sticks to help my daughter study stoichiometry.

How old is this poor daughter of yours?

17 months.

Best to start swotting physics early.

pftfweka

Surprisingly, she was pleased with this kit and mucked around with it for a couple of hours yesterday.

I mention in passing that selenocysteine is the one proteinogenic amino acid that involves something other than H, C, N, O, S.