(a) Why are Mn^(2+) compounds more stable than Fe^(2+) towards oxidation to their + 3 state? (b) What are interstitial compounds ? Why are such compounds well-known for transition metals ? (c) Write electronic configuration of Pm^(3+).

(a) Why are Mn^(2+) compounds more stable than Fe^(2+) towards oxidati

1.	(a) Why are Mn^(2+) compounds more stable than Fe^(2+) towards oxidation to their + 3 state? (b) What are interstitial compounds ? Why are such compounds well-known for transition metals ? (c) Write electronic configuration of Pm^(3+).
Answer» Solution :(a)`Mn^(2+) (3d^5 )-` exactlyhalffilledandectrastableand hashigh3rdionisationenthalpy`FE^(2+ ) ( 3d ^6 )` can loseelectron easilytoget`Fe^(3+)(3d^5)` i.e.,extrastableconfiguration (b )In suchcompounds the small atomssuchas `h,c ` B,Netcoccupyinterstitialsites in theirlatticeseg. TiC`TiH_2,Fe_3H`steeletcsuchcompoundsTransitionmetalsformsuchcompoundsbecausetheycantakeup smallatomsof C , h,B,N etcin theirinerstitialsitesin theirlattices (c ) ` PM^(3-1) (61-3=58e)` `1s^2 2s^2 2p^6 3s^2 3d^63d^(10) 4s^24p^(10)5s^2 5p^6 4f^4 "in" [Xe ]_54 4F^4 `