Advertisements
Advertisements
प्रश्न
Give reason for the following statement:
Physical and chemical properties of the 4d and 5d series of the transition elements are quite similar to expected.
Advertisements
उत्तर
Physical and chemical properties of 4d and 5d series elements are similar because they have same atomic and ionic radii due to the lanthanide contraction. Due to equal atomic radii the size of Zr and Hf, Nb and Ta, Mo and W, etc., the two elements of each pair have the same properties.
संबंधित प्रश्न
How would you account for the following?
Transition metals exhibit variable oxidation states.
What are the characteristics of the transition elements and why are they called transition elements?
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.
Why do transition metal ions possess a great tendency to form complexes?
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 |
Assertion (A): Cu cannot liberate hydrogen from acids.
Reason (R): Because it has positive electrode potential.
The spin magnetic moment of cobalt in the compound Hg [Co(SCN)4] is:-
Sodium this sulphate is used in photography because of its:-
Give reasons for the following statement:
Zn, Cd, and Hg are soft metals.
In order to protect iron from corrosion, which one will you prefer as a sacrificial electrode, Ni or Zn? Why? (Given standard electrode potentials of Ni, Fe and Zn are -0.25 V, -0.44 V and -0.76 V respectively.)
