I have asked this on Mastodon, as it was related to another post I made there, but I thought I would ask here too

Group 4 elements on the @compoundchem@mstdn.social infographic

Carbon, Silicon etc,

https://www.compoundchem.com/2013/12/29/group-4/

Whereas Wikipedia

https://en.wikipedia.org/wiki/Group_4_element

Suggests group 4 is Titanium, Zirconium, Most periodic tables are group 1,2 on the left, then there is a jump over the transition to group 3, Boron, Aluminum, Transition element groups are numbered IIIB, IVB (which wikipedia lists as group 4) 2nd group of the transition elements.

So which is correct here, or does it depend on the periodic table you are looking at?

Paul

https://en.wikipedia.org/wiki/Group_(periodic_table)

2 hours ago, paulsutton said:

I have asked this on Mastodon, as it was related to another post I made there, but I thought I would ask here too

Group 4 elements on the @compoundchem@mstdn.social infographic

Carbon, Silicon etc,

https://www.compoundchem.com/2013/12/29/group-4/

Whereas Wikipedia

https://en.wikipedia.org/wiki/Group_4_element

Suggests group 4 is Titanium, Zirconium, Most periodic tables are group 1,2 on the left, then there is a jump over the transition to group 3, Boron, Aluminum, Transition element groups are numbered IIIB, IVB (which wikipedia lists as group 4) 2nd group of the transition elements.

So which is correct here, or does it depend on the periodic table you are looking at?

Paul

Yes it can be confusing, as it has changed over the years. I still think of B and Al as group III and N and P as group V. But IUPAC has spoken, so it is all different now.

Personally I think the most rational system would be to number the columns within each block, so C would become gp 2 of the p-block.That’s because it seems to me the 4 blocks, s, p, d, f, are the most important primary classification for the elements, reflecting the last valence shell being filled according to the Aufbauprinzip.

But the periodic table is so old and so fundamental to chemistry that it is impossible to scrape off all the barnacles of history. One just has to learn to live with the different versions.

(And don’t get me started on why we name the blocks s, p, d and f. That’s another long story, to do with early spectroscopy.)

2 hours ago, exchemist said:

Personally I think the most rational system would be to number the columns within each block, so C would become gp 2 of the p-block.That’s because it seems to me the 4 blocks, s, p, d, f, are the most important primary classification for the elements, reflecting the last valence shell being filled according to the Aufbauprinzip.

Agreed. But even then, La and Lu conspire to bring disorder to the boundaries of the rare earths and transition metals, don't they? Perhaps best to keep it simple and leave the wrinkles to those qualified and remunerated to deal with wrinkles.

44 minutes ago, sethoflagos said:

Agreed. But even then, La and Lu conspire to bring disorder to the boundaries of the rare earths and transition metals, don't they? Perhaps best to keep it simple and leave the wrinkles to those qualified and remunerated to deal with wrinkles.

Oh sure there are always things like that going on round the edges. Chemistry is complex and messy. There are elements for which there is no agreement as to what the ground state electronic configuration really is, when valence subshells are very close in energy. And you can have a (slightly sterile) debate about whether Zn should be counted as a transition metal or not. And so on.

But in chemistry I have always felt it is the rule-breakers that provide a lot of the fun. A good rule has to account for say 90% of cases, but then the exceptions become more interesting in contrast - and thus easier to remember.

7 hours ago, paulsutton said:

I have asked this on Mastodon, as it was related to another post I made there, but I thought I would ask here too

Group 4 elements on the @compoundchem@mstdn.social infographic

Carbon, Silicon etc,

https://www.compoundchem.com/2013/12/29/group-4/

Whereas Wikipedia

https://en.wikipedia.org/wiki/Group_4_element

Suggests group 4 is Titanium, Zirconium, Most periodic tables are group 1,2 on the left, then there is a jump over the transition to group 3, Boron, Aluminum, Transition element groups are numbered IIIB, IVB (which wikipedia lists as group 4) 2nd group of the transition elements.

So which is correct here, or does it depend on the periodic table you are looking at?

Paul

It is a common misconception that there is one 'periodic table' that can be presented in several different forms.

But in fact the situation is more complicated than this

Yes indeed it does depend upon 'which table' you look at, so let us look at how this situation has arisen.

So what is the periodic table and what is a period ?

Early chemists discovered that the 'indivisible elements' could be listed in small groups with similar properies.

The main distinguishing property they could measure back then was atomic weight, so they listed the elements by AW.

Mendeleyev was the first to notice that it was more than just collections, he noticed a regularity in the occurence in the more interesting (to the chemists) regularity in those lists, even though there were some anomalies in place on the list.

This is the table he published in 1869.

The' periods' go across the table, left to right. And the groups (Gruppe) are tabulated vertically.

You can see he was a bit mixed up about group 4.

But the real question was and still is
"Which properties to you use to generate the categories ?"

The problem being that different categories will include or exclude different elements, although listing in order of atomic number moved several misplaced elements into a more coherent pattern.

This straightforward listing led to the form you are probably thinking of known as the 'long form'

This form has the advantage that atomic number indexes every element and can be presented in a reasonably compact form.

But Chemistry is about a whole lot more than atomic weight and atomic number - that is really for physicists.

Chemistry is about acids and alkalies, metals and non metals, chemical reactions and most particularly electrons and their role.

Considering electrons we arrive at 4 groups and 7 periods, which tells us where all the electrons are

This information can also be displayed in other ways and I am guessing that you have looked at one of these.

Finally a very modern version of the long table showing a few extra properties eg metal/non metal.

1 hour ago, studiot said:

It is a common misconception that there is one 'periodic table' that can be presented in several different forms.

But in fact the situation is more complicated than this

Yes indeed it does depend upon 'which table' you look at, so let us look at how this situation has arisen.

So what is the periodic table and what is a period ?

Early chemists discovered that the 'indivisible elements' could be listed in small groups with similar properies.

The main distinguishing property they could measure back then was atomic weight, so they listed the elements by AW.

Mendeleyev was the first to notice that it was more than just collections, he noticed a regularity in the occurence in the more interesting (to the chemists) regularity in those lists, even though there were some anomalies in place on the list.

This is the table he published in 1869.

The' periods' go across the table, left to right. And the groups (Gruppe) are tabulated vertically.

You can see he was a bit mixed up about group 4.

But the real question was and still is
"Which properties to you use to generate the categories ?"

The problem being that different categories will include or exclude different elements, although listing in order of atomic number moved several misplaced elements into a more coherent pattern.

This straightforward listing led to the form you are probably thinking of known as the 'long form'

This form has the advantage that atomic number indexes every element and can be presented in a reasonably compact form.

But Chemistry is about a whole lot more than atomic weight and atomic number - that is really for physicists.

Chemistry is about acids and alkalies, metals and non metals, chemical reactions and most particularly electrons and their role.

Considering electrons we arrive at 4 groups and 7 periods, which tells us where all the electrons are

This information can also be displayed in other ways and I am guessing that you have looked at one of these.

Finally a very modern version of the long table showing a few extra properties eg metal/non metal.

The fourth one is curious. I have never seen that before. Where does it come from?

Thanks for this, if nothing else it confirms there is no right or wrong way as there are multiple conventions, I know things change over time, some are agreed changes, simple things like spelling Sulphur as Sulfur for example

Does all the different group conventions make study more challenging or would a university / exam board use one convention.?

1 hour ago, exchemist said:

The fourth one is curious. I have never seen that before. Where does it come from?

From much much battered copy of Spice (my second copy. ( It was so good I had the first one stolen from me).

37 minutes ago, paulsutton said:

Thanks for this, if nothing else it confirms there is no right or wrong way as there are multiple conventions, I know things change over time, some are agreed changes, simple things like spelling Sulphur as Sulfur for example

Does all the different group conventions make study more challenging or would a university / exam board use one convention.?

Sulphur is UK spelling, Sulfur is US.

The americans have simplified quite few technical words.

I'm sorry we didn't 'learn the table' , as some schools.

Cambridge board never set any exam questions about the table itself in my day, only about the information it contained.

The point being that you have to know a lot of the information for the table to assume real significance.

The standard channel shaped long table was developed by about the 1920s.

After this a single 'hanging' lanthanide line was introduced, followed by the double line in 1940.

There are lots more in-between tables for those interested.

Edited March 9Mar 9 by studiot

1 hour ago, paulsutton said:

Thanks for this, if nothing else it confirms there is no right or wrong way as there are multiple conventions, I know things change over time, some are agreed changes, simple things like spelling Sulphur as Sulfur for example

Does all the different group conventions make study more challenging or would a university / exam board use one convention.?

You had better ask a current chemistry teacher, I think, rather than us old fogies.🙂 But for what it is worth, I would expect most UK exam boards would specify that IUPAC naming and labelling conventions should be taught and those would be used in examinations, the aim being to avoid confusing students and to rear them on the modern system.

1 hour ago, studiot said:

From much much battered copy of Spice (my second copy. ( It was so good I had the first one stolen from me).

I see. Seems to be from the early 1960s, so a few years before my time. I can see the logic. It's interesting to group silicon with both germanium and titanium.

2 hours ago, studiot said:

Sulphur is UK spelling, Sulfur is US.

Sulfur is IUPAC. Also, aluminium is IUPAC, so the Americans don't have it all their own way.

1 hour ago, KJW said:

Sulfur is IUPAC. Also, aluminium is IUPAC, so the Americans don't have it all their own way.

The International Union of Pure and Applied Chemistry (IUPAC) recognizes

sulfur (spelled with an 'f') as the preferred international spelling for element 16, a decision adopted in 1990. While the "ph" spelling (sulphur) is still used in the UK and some Commonwealth nations, "sulfur" is the standard for international scientific, chemical, and educational nomenclature.

OK so since 1990.

But note the Gogle AI then contradicts itself with the second sentence about the UK.

Looking quickly in post 1990 textbooks

Edexel in 2000 (High School advanced Level) had the ph spelling

MCQs in Pharmaceutical Calculation (pharmacists professional exam) had ph for sulphur but the f spelling for sulfathiazole.

Most post 200 pharmacy books prefer the f spelling.

So I expect the amercanisation of English to continue, considering the great resource imbalance.

3 hours ago, exchemist said:

You had better ask a current chemistry teacher, I think, rather than us old fogies.🙂 But for what it is worth, I would expect most UK exam boards would specify that IUPAC naming and labelling conventions should be taught and those would be used in examinations, the aim being to avoid confusing students and to rear them on the modern system.

I see. Seems to be from the early 1960s, so a few years before my time. I can see the logic. It's interesting to group silicon with both germanium and titanium.

1964. Mine is a 1966 reprint.

"It's interesting to group silicon with both germanium and titanium."
Chemically, they probably have more in common with each other than with carbon or lead.

I wait for Iupac, having decreed in favour of sulfur, to set their sights on "fosforus".
While we are at it, "helium should be "helion" or something, because it's not a metal.