99 Percentile Qs Bank for JEE MainChemistryClassification of Elements and Periodicity in Properties
The IE 1 of I st series of transition elements are as given: Ionisation energy in KJ / Mol Element Atomic number 0 . 65 Sc 21 0 . 64 Ti 22 0 . 64 V 23 0 . 68 Cr 24 0 . 72 Mn 25 0 . 76 Fe 26 0 . 75 Co 27 0 . 73 Ni 28 0 . 74 Cu 29 0 . 9 Zn 30 In general transition elements reacts: 1 s 2 , 2 s 2 , 2 p 6 , 3 s 2 , 3 p 6 , 3 d n , 4 s 2 → 1 s 2 , 2 s 2 , 2 p 6 , 3 p 6 , 3 d n How do you explain the ionisation of tra
Options
- AAs the electrons are removed from the 3 d orbitals, the energy of 3 d orbitals become lower than 4 s orbitals,
- BWhen the electrons are introduced to the 3 d orbitals, the energy of 3 d electrons become lower than that of 4
- CWhen electrons are removed cation having electrons in 3 d orbitals have lesser energies than the cation having
- DAll of the above.
Correct answer
C. When electrons are removed cation having electrons in 3 d orbitals have lesser energies than the cation having
Step-by-step solution
Greater the value of Z eff on 3 d electron than 4 s electron shows that 3 d electrons are tightly bound to the nucleus than 4 s electron. Due to this different force of attraction between electrons and nucleus cations having electrons in 3 d orbitals have lesser energies than the cation having electron in 4 s orbital.