What are transition elements? Write two characteristics of the transition elements.

Metals which have incomplete (or electrons filling into penultimate shell) d-shell either in their ground state or ionic state are called transition elements. Initially they were named ‘transition’ as they lie between s-block(metals) and p-block(non-metals).

Characteristics of transition elements:

1.They exhibit a variable oxidation state(each metal can exist in more than one oxidation state). Eg: manganese exists as Mn⁺², Mn³⁺, Mn⁵⁺, Mn⁷⁺

2.They are paramagnetic in nature. As most of them have unpaired electrons they are attracted towards the magnetic field hence paramagnetic.

3.They form coloured compounds. When the electron gets excited from the ground state to higher energy d-orbitals, the energy absorbed lies in visible light region, hence observe the complementary colour to the colour absorbed.

4.They form complex compounds. These metals or their ions have the ability to bind with multiple anions or neutral molecules giving complex species with characteristic properties.

5. They exhibit catalytic properties, this is due to their multiple oxidation states and ability to form complexes.