What is the general name of the elements having 8 electrons in the valence shell of their atoms?

The electronic configuration of an element Z is 2, 8, 8.

(a) What is the atomic number of the element?

(b) State whether element Z is a metal or a non-metal.

(c) What type of ion (if any) will be formed by an atom of element Z? Why?

(d) What is special about the outermost electron shell or the atom of this element?

(e) Give the name and symbol of element Z.

(f) Name the group of elements to which Z belongs.

The total number of electrons in a nitrogen atom is 7. Find the number of valence electrons in it.

Which noble gas has less than 8 electrons in the valence shell of its atom? What is this number?

State one use of radioactive isotopes in medicine.