Amolecule contains five atoms and has a molecular weight of 85 g per mole. the atoms are of elements with atomic numbers 1, 6, and 17. which molecular structure could represent this molecule?

            Dichloromethane

Explanation:

As we know the atomic number given belongs to following elements, i.e.

Atomic #                   Element                      M.Mass

   1                           Hydrogen                    1 g.mol⁻¹

   6                          Carbon                        12 g.mol⁻¹

   17                         Chlorine                      35.5 g.mol⁻¹

Also the molecular formula of Dichloromethane is,

                           =  CH₂Cl₂

Putting molar masses of each element,

                          =  (12)₁  +  (1)₂  +  (35.5)₂

                          =  12  +  2  +  71

                          =  85 g.mol⁺¹

Result:

         Hence the only possible structure containing 5 atoms is Dichloromethane.

the answer is 0.42 is that is an option. this question provides no info