Final answer:
In a molecule of formula C₃H₄F₂, the total number of valence electrons is 22.
Step-by-step explanation:
To determine the number of valence electrons in the molecule C₃H₄F₂, you need to look at the valence electrons of each atom present.
The carbon atom (C) has 4 valence electrons, while each hydrogen atom (H) has 1 valence electron. Fluorine (F) has 7 valence electrons, but since there are 2 fluorine atoms in the molecule, the total number of valence electrons contributed by the fluorine atoms is 2 x 7 = 14.
Adding up the valence electrons from each atom, we get: 4 (carbon) + 4 (hydrogen) + 14 (fluorine) = 22. Therefore, the correct option is 22.