CBSE Class 11-science Answered

The transition elements are all metals. If we compare transition elements with a few of the most similar main group elements we will find that there are just a few characteristic differences.

• They make brightly coloured compounds, especially with their salts.

• They show variable valency, which most main group elements do not.

• They make a wide variety of "co-ordination complexes". Many of the other main group metals do not.

• A characteristic of transition metals is that they exhibit two or more oxidation states, usually differing by one. Main group elements in groups 13 to 17 also exhibit multiple oxidation states. The "common" oxidation states of these elements typically differ by two. The main difference in oxidation states, between transition elements and other elements is that oxidation states are known in which there is a single atom of the element and one or more unpaired electrons.