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प्रश्न
Give a reason for the following:
Zinc, cadmium and mercury are considered as d-block elements but not regarded as transition elements.
उत्तर
Transition metals are elements that have partially filled d-orbitals. Due to the completely filled d orbitals in their ground state and a common oxidation state of +2. Zinc, cadmium and mercury are classified as d-block elements, but not as transition elements.
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संबंधित प्रश्न
How would you account for the following?
Transition metals and their compounds act as catalysts.
Why do transition metal ions possess a great tendency to form complexes?
Two metallic elements A and B have the following standard oxidation potentials: A = 0·40v B = - 0·80v. What would you expect if element A was added to an aqueous salt solution of element B? Give a reason for your answer.
Transition elements form binary compounds with halogens. Which of the following elements will form \[\ce{MF3}\] type compounds?
(i) \[\ce{Cr}\]
(ii) \[\ce{Co}\]
(iii) \[\ce{Cu}\]
(iv) \[\ce{Ni}\]
Transition elements show high melting points. Why?
Although fluorine is more electronegative than oxygen, but the ability of oxygen to stabilise higher oxidation states exceeds that of fluorine. Why?
Identify the metal and justify your answer.
Carbonyl \[\ce{M(CO)5}\]
Which of the following statements is not correct?
The basic character of transition metals monoxide follow the order.
For M2+/M and M3+/M2+systems, the EΘ values for some metals are as follows:
| Cr2+/Cr | −0.9 V |
| Mn2+/Mn | −1.2 V |
| Fe2+/Fe | −0.4 V |
| Cr3/Cr2+ | −0.4 V |
| Mn3+/Mn2+ | +1.5 V |
| Fe3+/Fe2+ | +0.8 V |
Use this data to comment upon:
The ease with which iron can be oxidised as compared to a similar process for either chromium or manganese metal.
