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प्रश्न
Which of the d-block elements may not be regarded as the transition elements?
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उत्तर
The electronic configuration of Zn, Cd and Hg is represented by the general formula (n – 1)d10ns2. In these elements, the orbitals are completely filled in the ground (normal) state as well as in ordinary oxidation states, i.e., the subshells are not incomplete in their atomic state or any one of the ionic states. Therefore, they cannot be called transition elements.
संबंधित प्रश्न
Calculate magnetic moment of `Fe_((aq))^(2+) ion (Z=26).`
To what extent do the electronic configurations decide the stability of oxidation states in the first series of the transition elements? Illustrate your answer with examples.
Predict which of the following will be coloured in the aqueous solution?
Ti3+, V3+, Cu+, Sc3+, Mn2+, Fe3+ and Co2+. Give reasons for each.
Following are the transition metal ions of 3d series:
Ti4+, V2+, Mn3+, Cr3+
(Atomic numbers: Ti = 22, V = 23, Mn = 25, Cr = 24)
Answer the following:
1) Which ion is most stable in an aqueous solution and why?
2) Which ion is a strong oxidising agent and why?
3) Which ion is colourless and why?
Complete and balance the following chemical equations
`MnO_4^(-) + H_2O + I^(-) ->`
Why do transition elements show variable oxidation states ? In 3d series (Sc to Zn), which elements shows the maximum number of oxidation state and why ?
Explain why transition elements form alloys.
Explain why Zn2+ salts are white whereas Cu2+ salts are coloured.
Explain why transition metals and their compounds act as a catalyst.
Maximum oxidation state is shown by ____________.
Metallic radii of some transition elements are given below. Which of these elements will have highest density?
| Element | \[\ce{Fe}\] | \[\ce{Co}\] | \[\ce{Ni}\] | \[\ce{Cu}\] |
| Metallic radii/pm | 126 | 125 | 125 | 128 |
Which of the following ions show higher spin only magnetic moment value?
(i) \[\ce{Ti^3+}\]
(ii) \[\ce{Mn2+}\]
(iii) \[\ce{Fe2+}\]
(iv) \[\ce{Co3+}\]
Reactivity of transition elements decreases almost regularly from Sc to Cu. Explain.
Fill in the blanks by choosing the appropriate word(s) from those given in the brackets:
(activation energy, Threshold energy, increased, lowered, partially, full, d-d transition, Benzoic acid, benzaldehyde)
Only those transition metal ions will be coloured which have ______ filled d-orbitals facilitating ______.
Why are fluorides of transition metals more stable in their higher oxidation state as compared to the lower oxidation state?
Which of the following is non-metallic?
Account for the following:
Transition metals form alloys.
Account for the following:
Sc3+ is colourless whereas Ti3+ is coloured in an aqueous solution.
Explain the use of different transition metals as catalysts.
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:
Oxidation states
