To determine the number of valence electrons in C2H5OH, we first identify the number of valence electrons contributed by each type of atom in the molecule.
1. **Carbon (C)**: There are 2 carbon atoms, and each carbon has 4 valence electrons. Therefore, for carbon:
2 C × 4 = 8 valence electrons.
2. **Hydrogen (H)**: There are 6 hydrogen atoms, and each hydrogen has 1 valence electron. Hence, for hydrogen:
6 H × 1 = 6 valence electrons.
3. **Oxygen (O)**: There is 1 oxygen atom, which has 6 valence electrons. So for oxygen:
1 O × 6 = 6 valence electrons.
Now, we sum all the valence electrons from each atom:
8 (from C) + 6 (from H) + 6 (from O) = 20 valence electrons.
In conclusion, C2H5OH has a total of 20 valence electrons.