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प्रश्न
Why are interstitial compounds well known for transition metals?
उत्तर
Interstitial compounds do not correspond to any normal oxidation state of the metal. Because of the nature of their composition, these compounds are referred to as interstitial compounds. The principal physical and chemical characteristics of these compounds are as follows:
- They have high melting points, higher than those of pure metals.
- They are very hard; some borides approach diamond in hardness.
- They retain metallic conductivity.
- They are chemically inert.
संबंधित प्रश्न
Compare the general characteristics of the first series of the transition metals with those of the second and third series metals in the respective vertical columns. Give special emphasis on the following point:
Electronic configurations
Write balanced chemical equations for the conversion of `CrO_4^(2-)` to `Cr_2O_7^(2-)` in acidic medium and `Cr_2O_7^(2-)` to `CrO_4^(2-)`
in basic medium.
Complete and balance the following chemical equations
`Fe^(2+) + MnO_4^(-) + H^+ ->`
Give reasons: E° value for the Mn3+/Mn2+ couple is much more positive than that for Fe3+/Fe2+.
Although Zirconium belongs to 4d transition series and Hafnium to 5d transition series even then they show similar physical and chemical properties because ______.
The orientation of an atomic orbital is governed by
Why Zn, Cd and Hg are not called transition metals?
Account for the following:
Sc3+ is colourless whereas Ti3+ is coloured in an aqueous solution.
The second ionization enthalpies of chromium and manganese are 1592 and 1509 kJ/mol respectively. Explain the lower value of Mn.
Decide which of the following atomic numbers are the atomic numbers of the inner transition elements:
29, 59, 74, 95, 102, 104
