Identify diamagnetic ion from following. (Atomic no.of Na=11, Cu=29, Fe=26, Cr=24)
Identify diamagnetic ion from following. (Atomic no.of Na=11, Cu=29, Fe=26, Cr=24)
  1. Cu2+
  2. Fe3+
  3. Na+
  4. Cr3+

Solution:  Na+

Cu2+ = 1s22s22p63s23p63d9

Fe3+ = 1s22s22p63s23p63d5

Cr3+ = 1s22s22p63s23p63d3

Na+ = 1s22s22p6

All the given ions except Na+ have unpaired electrons in their outermost shells ( odd number of electrons). Therefore, sodium ion is the diamagnetic ion.