Consider the following species when answering the following question:
(i) nf3
(ii) bf3
(iii) if3
(iv) pbr3
(v) brcl3
of the molecules below, only is nonpolar.
bf3
nf3
pbr3
brcl3
if3

Only BF₃ is non polar.

Explanation:

The non polar molecule is one which will have zero dipole moment.

This zero dipole moment is possble if

a) the bonds are non polar (completely) and there is no lone electrons

b) the bonds are polar but the overall dipole moment cancel each other due to planar geometry of molecule

i) BF₃ : This is trigonal planar molecule. The overall dipole moment is zero due to symmetric distribution of electrons and thus dipole cancel each other.

ii) NF₃ : there is lone pair of electron and the bonds are polar.

iii) PBr₃: Again presence of lone pair of electrons and thus ssymmetric distribution of electrons

iv) BrCl₃ : The bonds are polar and molecule is not planar.

v) IF₃ : bonds are polar.

in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

explanation: