How many elements of unsaturation does a molecule with the chemical formula C5H8 have?

 Unsaturation in a molecule refers to the presence of double or triple bonds between the carbon atoms or the presence of a ring structure. To determine the number of elements of unsaturation in a molecule, you can use the following formula:

Number of elements of unsaturation = (2 x number of rings) + (2 x number of double bonds) + (3 x number of triple bonds)

In the case of C5H8, the molecule has no double bonds, triple bonds, or ring structures, so the number of elements of unsaturation is 0.