The element that does not belong to the same period of the remaining elements (modern periodic table) is:

The d-electronic configuration of an octahedral Co (II) complex having magnetic moment of 3.95 BM is:

The complex that shows Facial - Meridional isomerism is :

Heat treatment of muscular pain involves radiation of wavelength of about 900 nm . Which spectral line of H atom is suitable for this?

Given : Rydberg constant $\left.\mathrm{R}_{\mathrm{H}}=10^5 \mathrm{~cm}^{-1}, \mathrm{~h}=6.6 \times 10^{-34} \mathrm{~J} \mathrm{~s}, \mathrm{c}=3 \times 10^8 \mathrm{~m} / \mathrm{s}\right)$