In the complex [Fe(H2O)6]2+, how many number of unpaired electrons are present?

3 4 5 6

4

In [Fe(H2O)6]2+  x + 6(0) = 2 x = 2 26Fe : [Ar]4s23d6 Fe2+ : [Ar]3d6  ↑↓ ↑ ↑ ↑ ↑   There are 4 unpaired electrons.