Question

Which subshell is represented by the actinides family?
Which subshell is represented by lanthanides family?

Answer 1

4f orbitals for the lanthanides
5f orbitals for actinides

source: Uni. Student
source 2: http://www.mikeblaber.org/oldwine/chm1045/notes/Struct/EPeriod/IMG00011.GIF

Answer 2

thank you kindly another question can you help

Answer 3

sure

Answer 4

Why is the transition metals 10 columns wide?

Answer 5

To be completely honest I'm not sure, but I can give you a kind of explanation to it. It's mostly a history thing that goes as follows: a Russian Chemist named Mendeleev created a table of elements of which he arranged the elements through their atomic mass, and left holes in between the tables for elements that are yet to be discovered. Through the years people added elements to it and started to discover things like nucleons, radiation, etc..., and at some point in the 20th century people realized that the atomic mass doesn't really change the properties, so they decided to arrange them by atomic number of which the properties change significantly. So they reorganized it in atomic number, keeping in consideration their properties, such as radiation and electrons, protons, etc....

Another way to look at is columns 1 and 2 have a possibility of 2 electrons in the 's' orbital, while rows 13-18 have a possibility of 6 electrons in the 'p' orbital, columns 3-13 have a possibility of 10 electrons in the 'd' orbital, and actinides and lanthanides have a possibility of 14 electrons in the 'f' orbital. So they pretty much organised by how many electrons are possible in each of their shells...(electron configuration)

I have no clue is this is the answer to your question....