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प्रश्न
Account for the following:
Eu2+ with electronic configuration [Xe]4f76s2 is a strong reducing agent.
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उत्तर
Because it is more stable than Eu, Eu2+ is a powerful reducing agent. After removing two electrons, the electronic configuration is 4f76s2, resulting in a half-filled (f) electronic configuration that acts as a strong reducing agent.
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संबंधित प्रश्न
Complete the following chemical equations:
`(i) Cr_2O_7^(2-)+6Fe^(2+)+14H^+ ->`
`(ii) 2CrO_4^(2-)+2H^+ ->`
`(iii) 2MnO_4^-+5C_2O_4^(2-)+16H^+ ->`
Why do the transition elements have higher enthalpies of atomisation?
In 3d series (Sc to Zn), which element has the lowest enthalpy of atomisation and why?
Which among the following transition metal has the lowest melting point?
Transition metals with highest melting point is ____________.
Read the passage given below and answer the following question:
The transition metals when exposed to oxygen at low and intermediate temperatures form thin, protective oxide films of up to some thousands of Angstroms in thickness. Transition metal oxides lie between the extremes of ionic and covalent binary compounds formed by elements from the left or right side of the periodic table. They range from metallic to semiconducting and deviate by both large and small degrees from stoichiometry. Since electron bonding levels are involved, the cations exist in various valence states and hence give rise to a large number of oxides. The crystal structures are often classified by considering a cubic or hexagonal close-packed lattice of one set of ions with the other set of ions filling the octahedral or tetrahedral interstices. The actual oxide structures, however, generally show departures from such regular arrays due in part to distortions caused by packing of ions of different size and to ligand field effects. These distortions depend not only on the number of d-electrons but also on the valence and the position of the transition metal in a period or group.
In the following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices on the basis of the above passage.
Assertion: Cations of transition elements occur in various valence states.
Reason: Large number of oxides of transition elements are possible.
Answer the following question:
Which element of the first transition series has lowest enthalpy of atomisation?
On strong heating AgNO3, the gases evolved are:-
Which of the following ions will exhibit colour in aqueous solution?
Give reasons for the following statement:
Transition metals and most of their compounds show paramagnetic behaviour.
