What are transition elements and inner transition elements.State the position of the inner transition elements .State why noble gases are considered unreactive elements
The elements which have partially filled d-orbitals either in ground state or in one or more of their ions are called d-block elements or transition elements. Their properties are intermediate between s-block elements and p-block elements. They are more electropositive than p-block elements but less electropositive than s-block elements. They are all metals and have electronic configuration ns 2 (n-1)d 1 to 10
Inner Transition elements: These are the f-block elements placed below the periodic table but they belong to 6 and 7 group within the transition series.The electronic configuration of inner transition elements is: (n-2) f 0-14(n-1) d 0-2 ns 2 .These are divided into two series: Lanthanides (atomic numbers 58-71) and actinides(atomic numbers 90-103).
Position of Inner Transition elements:- The Inner Transition Metals are found in the bottom two rows of the periodic table.They include elements Lanthanides (atomic numbers 58-71) and actinides(atomic numbers 90-103).
By octet rule, any atom participate in a chemical reaction in order to compete 8 electrons in its valence shell.
But the valence shell of noble gases is already full, so they do not participate in any reaction and are unreactive.