IS THE PERIODIC TABLE A KID OR A TEENAGER?

[Gian]

The BBC's GCSE Chemistry page says there are eight 8 groups in the Periodic Table; 1-7, plus 0 (noble gases?) But there are ten columns between 2 and 3 with no number:
https://www.bbc.co.uk/bitesize/articles/zptfn9q#zkn27yc


However, other versions of the Table like this one from the The Royal Society of Chemistry show 18, eighteen groups. What's going on??
https://www.rsc.org/periodic-table

I should emphasise that age 32 I'm pre-GCSE level so my science age is about 12½  please keep answers as simple as possible

Cheerz

GCSE GIAN😊XXX

science age 12½

[studiot]

The Periodic Table

 

Hmm  -  An interesting place to start your study of chemical bonding.

 

To have any sort of periodic table at all it was necessary to identify enough different 'elements' to arrange.
This was achieved between the late 17 hundreds and the early 18 hundreds.

At that time there was no such idea as 'atomic number' (ask if you need to know what this is).
Known elements were arranged by atomic weight  - although this was not as easy as it seemed and the first Internation Conference in Chemistryheld in 1860 was intended to produce proper definitive definitions for 'atom',  'molecule', 'radical'  and 'equivalent' but ended without achieving this.

However some of the participants, including Mendeleyev,  left with the the suggestion by Cannizzaro to abandon the weight order.

Chemists up to that time has followed the classical mathematical connection between music (yes music in the guise of harmonic scales) and science.

There was Dobereiner's triads or rule of 3

• Triad 1. Lithium: Sodium: Potassium: ...
• Triad 2. Calcium: Strontium: Barium: ...
• Triad 3. Chlorine: Bromine: Iodine: ...
• Triad 4. Sulfur: Selenium: Tellurium: ...
• Triad 5. Iron: Cobalt: Nickel:

 

and Newlands rule of rule of octaves

which led to the first 'periodic table'

 

 

https://byjus.com/chemistry/newlands-law-octaves/

https://www.simply.science/images/content/chemistry/structure_of_matter/dev_of_periodic_table/conceptmap/Newlands_Law.html

 

Following the switch to 'atomic number'  Mendeleyev was able to place the 63 known elements in their proper position in a table.

But they did not know why or about the other 55 naturally occurring elements ( or the radioactive ones).

 

Since that time there have been many attempts to extend the table and it has been found necesary to split the original 8 columns to incorporate new subcolumns.
Different arrangements do this differently.

 

Have you ever been to the Science Museum ?

It is really worth a visit if you can get there, here is their offering on the subject.

Quote

The periodic table is one of the most iconic images in science, a guide to the chemistry of our world. But it's only one among many visual ways to classify the elements.

There are thousands of alternative periodic tables or systems, some predating the invention of the now-standard version you might know from the school chemistry lab.  

https://www.sciencemuseum.org.uk/objects-and-stories/chemistry/developing-modern-periodic-table-spirals-stars

 

OK so where are we today ?

 

Well we are moving away from periodic tables of chemical properties alone, bearing in mind radioactivity and what we now know about the structure of the atom.

A new term 'nuclide' has entered the scene and the 'table' often now takes the form of a plot  N (the number of neutrons) against Z (the number of protons)

This is known as a Segre Chart

 

https://www.radiologycafe.com/frcr-physics-notes/basic-science/atomic-structure/

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

[KJW]

This may help:

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