Answer:
The first row of elements fits in period 6, after the element lanthanum (La). The second row of elements fits in period 7, after the element actinium (Ac).
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The characteristics of the periodic table allows to find the results for the location of rare earths are:
The periodic table is an arrangement of the chemo elements based on their atomic number, each row begins with an element with 1 electron in its last shell and ends with 8 electrons in its last shell.
The rows of the periodic table are called the period and the columns are called the group. The elements of the same group have the same number of electrons in their last layer.
The way to order the periodic table is based on the energy of each element in its chemical configuration, the lower energy sublevels are filled first, using calculations the order of filling the orbital levels is:
s f d p
The separate groups of the periodic table correspond to elements that are filled in the sublevel f that can hold 14 electrons, therefore there are 14 elements for each period. The elements of these two rows are collectively called Rare Earths, see attached.
The first group the Lanthanides are in period number 6 and everything has 3 electrons in its last shell, therefore they are in group 3, where the element Lanthanum is.
Everyone is in this box since they are filling their inner layer f.
The second group Actinides are in period 7 and group 3, in the position of the element Actinium.
All this filled its inner level f that it can hold 14 electrons.
In conclusion using the characteristics of the periodic table we can find the results for the location of the rare earths are:
Learn more here: brainly.com/question/11155928
