Actinides and Lanthanides group I would like to ask which group do actinide and lanthanide belong?
I had a question in my assingment that which group has most number of elements?
if they belong to 3rd group then the 3rd group should be the answer.
Am I wrong or Right? Please Help Me.
The periodic table actually looks like this:



...you can see that the first 14 elements in either series don't belong to any group from the main body of the table.

You could say that the lanthanides and actinides form fourteen new 2-element groups, with Lu and Lr belonging to group 3. But IUPAC does not number these groups: