what are elements of group 3 to 12 called in a modern periodic table?
Elements of group 3 to 12 called in a modern periodic table are called d-block elements. They are situated in between the s-block and p-block elements. They are called d-block as the last electron in these elements enters into the d-sublevel of the penultimate main energy level. E.g., Fe (26) = 1s2,2s2,2p6,3s2,3p6,4s2,3d6. They are also popularly called transition elements as their properties are in between those of s-block and p-block elements. They show characteristic features like hard metallic character, ferromagnetism (in some elements though), variable oxidation state, formation of coloured ions, tendency to form complexes and markedcatalytic activity.
They are called as d-block or trasition metals. They are called d-blok as the electronic configuration of these metals constain d-orbitals and trasition as they have variable oxidation state. Like Fe it has 2+ and 3+
The elements of group 3 to 12 are named the transition metals.