Understanding Lanthanide Series & Groupings in Periodic Tables

[Jimmy Snyder]

I have seen many types of periodic tables which I gather into 3 categories based on how they handle the Lanthanide series (and the Actinide series is handled in an analogous way). The tables do not say the things I say below, but they imply it by the layout.

1. Lanthanum is in group 3, but not in the Lanthanide series. The Lanthanide series includes Cerium through Lutetium. The Lanthanide series is not in any group.
ex: http://periodic.lanl.gov/default.htm

2. Lutetium is in group 3, but not in the Lanthanide series, The Lanthanide series includes Lanthanum through Ytterbium. The Lanthanide series is not in any group
ex: http://www.webelements.com/webelements/scholar/

3. The Lanthanide series includes Lanthanum through Lutetium. The entire Lanthanum series is in group 3.
ex: http://en.wikipedia.org/wiki/Periodic_table_(standard)

Can we say that one of these correctly depicts theory? Or is it a case of differing, but defensible points of view?

 

[Jimmy Snyder]

Never mind. I found the answer here:
http://en.wikipedia.org/wiki/Group_3_element

 

[ravenprp]

All three of these periodic tables are technically correct and depict different ways of organizing the Lanthanide series. However, the first two tables are more commonly used and accepted in the scientific community.

The first table, from the Los Alamos National Laboratory, is based on the electronic configuration of the elements. Lanthanum is in group 3 because it has three valence electrons, but it is not considered part of the Lanthanide series because it does not have the characteristic f-orbital electron configuration of the rest of the elements in the series.

The second table, from WebElements, is based on the chemical and physical properties of the elements. Lutetium is in group 3 because it shares similar properties with the other group 3 elements, such as scandium and yttrium. However, it is not considered part of the Lanthanide series because its electron configuration is different from the other elements in the series.

The third table, from Wikipedia, is a more simplified version of the periodic table and includes the entire Lanthanide series in group 3. This is a valid way of organizing the elements, but it does not accurately reflect the unique properties and characteristics of the Lanthanide series.

In conclusion, while all three tables are correct in their own way, the first two are more commonly accepted and used in the scientific community due to their focus on the electronic configuration and chemical properties of the elements. It is important to understand the different ways of organizing the periodic table and the reasoning behind each approach.