Reaction of [Co(H₂O)₆]²⁺ with excess ammonia and in the presence of oxygen results into a diamagnetic product. Number of electrons present in t_2g-orbitals of the product is ___________.

The spin-only magnetic moment value of an octahedral complex among CoCl₃.4NH₃, NiCl₂.6H₂O and PtCl₄.2HCl, which upon reaction with excess of AgNO₃ gives 2 moles of AgCl is ___________ B.M. (Nearest integer)

Amongst FeCl₃.3H₂O, K₃[Fe(CN)₆] and [Co(NH₃)₆]Cl₃, the spin-only magnetic moment value of the inner-orbital complex that absorbs light at shortest wavelength is ____________ B.M. [nearest integer]

If [Cu(H₂O)₄]²⁺ absorbs a light of wavelength 600 nm for d-d transition, then the value of octahedral crystal field splitting energy for [Cu(H₂O)₆]²⁺ will be ____________ $$\times$$ 10^$$-$$21 J. [Nearest Integer]

(Given : h = 6.63 $$\times$$ 10^$$-$$34 Js and c = 3.08 $$\times$$ 10⁸ ms^$$-$$1)