Electrongativity is not applicable for the element with configuration

Which element has duplet configuration?

Some of the properties which depend on electronic configuration elements are - atomic radii, ionisation potential, and electronegativity etc. The element with maximum electrongativity belongs to :

The elements with electronic configuration (2,7)

There are 4 electrons in the M shell of an element. Write the electron configuration of the element.

What are transition elements? Give the general electronic configuration of transition elements.

The Law of Octaves was found to be applicable to elements