The number of unpaired electrons in a carbon atom in the excited state is:

Electronic configuration of deuterium atom is

The electronic configuration of the phosphide ion is similar to which of the following?

Electronic configuration of $H^{-}$ is

The order of filling of electrons in orbitals in $Ti$ is

The electrons,identified by quantum numbers $n$ and $l$ as $(i) n = 4, l = 1$,$(ii) n = 4, l = 0$,$(iii) n = 3, l = 2$,$(iv) n = 3, l = 1$,can be placed in order of increasing energy,from the lowest to highest,as: