Highest (+7) oxidation state is shown by
Mercury is the only metal which is liquid at 0oC . This is dueto its
Very high ionisation energy and weak metallic bond.
A transition element X has a configuration [Ar]3d4 in its + 3oxidation state. Its atomic number is
Number of electrons in excited stateX+3 = 18 + 4 = 22Number of electrons in ground stateX = 22+3 = 25 .
The lanthanide contraction is responsible for the fact that