Q1.. Answer the following parts:
- (a)) Explain the trends of ionization energy down the groups of the elements in the periodic table. How are the higher values of ionisation energies of the 5d transition elements justified? (300 words)
- (b)) What is the trend of the stability of the +6 state for Group 6 elements like tungsten, molybdenum and chromium? Which other group show a similar trend? Justify your answer. (300 words)
- Ionization energy generally decreases down a group due to increased atomic radius and shielding.
- 5d transition elements have anomalously high ionization energies due to lanthanide contraction.
- Relativistic effects in heavy elements contract s/p orbitals, increasing ionization energy for 5d elements.
- Stability of +6 oxidation state for Group 6 (Cr, Mo, W) increases down the group.
Answer: Ionization energy, a fundamental periodic property, generally decreases down a group due to increasing atomic size and shielding effects. However, 5d transition elements exhibit anomalously high ionization energies, often exceeding those of their 4d counterparts, a phenomenon attributed to lanthanide contraction and relativistic effects. Similarly, the stability of higher oxidation states, such as the +6 state for Group 6 elements (Cr, Mo, W), typically increases down the group, a trend also obs...