Question

How to locate the position of element with atomic number 120 which is not yet discovered ?

Answer 1

You use the order of filling orbitals and your knowledge of the Periodic Table to locate Element 120.

Explanation:

The known elements

The last known element in the Periodic Table is Element 118, `"Og"` (oganesson).

(From Fotolia,com)

It is in the lower right-hand corner of the Periodic Table, at the end of Period 7 and the bottom of Group 18.

It is the last element in the `"p"` block, so its electron configuration ends in `"7p"^6`.

Where is element 120?

We use the order of filing atomic orbitals.

(Adapted from Wikibooks)

It shows that the next electrons will go into the `"8s"` orbital.

The `"s"` block is at the left-hand side of the Periodic Table, and the `"8s"` orbital can hold two electrons.

That’s just enough electrons to get us from `"Og"` to element 120.

(From www.chemicool.com)

You will find it under radium (at. no. 88), so it should be an alkaline earth metal.