The metal d-orbitals that are directly facing the ligands in K₃[Co(CN)₆] are -

The molecule that has minimum /no role in the formation of photochemical smog, is :

Among the following compounds most basic amino acid is -

Decomposition of X exhibits a rate constant of 0.05 $$\mu $$g/year. How many year are required for the decomposition of 5$$\mu $$g of X into 2.5 $$\mu $$g?