3 public questions tagged with this topic.
In period 5 d-block (Y to Cd), Tc (group 7) achieves a +7 oxidation state (e.g., in Tc₂O₇) due to the availability of d-electrons, unlike Zr, Nb, or Mo.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Genesis of Periodic Classification - Dobereiner Newlands Mendeleev
In period 5 d-block (Y to Cd), electronegativity increases across. Pd (group 10) has the highest electronegativity due to its position and nuclear charge.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Genesis of Periodic Classification - Dobereiner Newlands Mendeleev
In period 5 d-block (Y to Cd), melting point peaks with strong metallic bonding. Mo (group 6, 4d⁵ 5s¹) has the highest melting point due to maximum unpaired electrons.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Electron Gain Enthalpy and Electronegativity and Valency
