Question

The correct option with order of melting points of the pairs (Mn, Fe), (Tc, Ru) and (Re, Os) is:

• A. \( {Fe}<{Mn}, \ {Ru}<{Tc} \ {and} \ {Re}<{Os} \)
• B. \( {Mn}<{Fe}, \ {Tc}<{Ru} \ {and} \ {Os}<{Re} \)
• C. \( {Mn}<{Fe}, \ {Tc}<{Ru} \ {and} \ {Re}<{Os} \)
• D. \( {Fe}<{Mn}, \ {Ru}<{Tc} \ {and} \ {Os}<{Re} \)

Hint:

When comparing the melting points of transition metals, consider factors like atomic number, crystal structure, and bonding strength.

Answer 1

The Correct Option is C

- The melting point of Mn is lower than Fe because Mn has a lower atomic number and a less stable crystal structure compared to Fe. 
- The melting point of Tc is lower than Ru due to the differences in atomic structure and bonding. 
- The melting point of Re is lower than Os because Os has a higher atomic number and stronger metallic bonding, leading to a higher melting point. Thus, the correct answer is \( {Mn}<{Fe}, \ {Tc}<{Ru} \ {and} \ {Re}<{Os} \).