The hybridization of atomic orbitals of central atoms in CO2, BF3 and NH4+ respectively are:

Explanation

The hybridization of atomic orbitals of central atoms in CO2, BF3, and NH4+ are sp, sp2, and sp3, respectively. CO2 is a linear molecule with a triple bond between the carbon and oxygen atoms. The carbon atom is sp hybridized, which means that it has two sp orbitals. The two sp orbitals are used to form the two C=O bonds, and there are no lone pairs of electrons on the carbon atom. BF3 is a trigonal planar molecule with three single bonds between the boron and fluorine atoms. The boron atom is sp2 hybridized, which means that it has three sp2 orbitals. The three sp2 orbitals are used to form the three B-F bonds, and there is one lone pair of electrons on the boron atom. NH4+ is a tetrahedral molecule with four single bonds between the nitrogen and hydrogen atoms. The nitrogen atom is sp3 hybridized, which means that it has four sp3 orbitals. The four sp3 orbitals are used to form the four N-H bonds, and there are no lone pairs of electrons on the nitrogen atom.