The elements that have partially filled d orbital are called as Transition elements.
Transition elements are the d-block elements forming group 3 to group 11 in the modern periodic table. The inner transition elements i.e. lanthanides and actinides in the f -block also meet this criteria of transition elements. The copper family (group 11) have fully filled d-orbitals and as group 12 elements do not show some of the chemical properties of transition elements, but most of the times elements of group 11 are considered as a part of the transition elements.
The elements from group 4-11 are known as recognition metals. They form a wide range of ions having various oxidation states and posses catalytic properties with many coloured complexes. The elements from Ce-Lu are considered as “Lanthanide” series and from Th-Lr are known as “Actinide” series, they form the f block elements of the modern periodic table and are known as the ‘inner transition elements’.
Some elements like zinc, mercury and cadmium do not show the transition metal properties as their outer shell electronic configuration has fully filled d orbital.
The general electronic configuration of d block elements is (n-1)d1-10 ns1-2.
Characteristics properties of transition elements:
- Due to partially filled d-orbitals, transition elements show a number of properties that are not found in other elements.
- Due to d-d electronic transition these elements show color in their compounds.
- Due to comparatively low energy gap between the oxidation states they show various oxidation states.
- Due to the presence of unpaired d electrons some of these elements show paramagnetic properties.
- Both heterogeneous as well as homogeneous catalytic property is shown by transition metals.
Transition metals and their chemistry has been an important subject of research for scientists. The developments in inorganic chemistry has enabled scientists to design efficient reaction systems and specific catalysts that are economically efficient too. For any further support download Byju’s- The Learning App.