I apologize for the confusion in my previous response. In the case of Fe(CO)5, the total number of valence electrons would be 16, not 18. Let's break down the electron count for Fe(CO)5:
Fe: Iron (Fe) is in Group 8, so it has 8 valence electrons.
CO: Carbon (C) is in Group 4, so it has 4 valence electrons. Oxygen (O) is in Group 6, so it has 6 valence electrons. Since there are five CO ligands, we multiply the number of valence electrons by 5: 5 × (4 + 6) = 50 valence electrons.
Adding the valence electrons from Fe and CO:
Fe: 8 valence electrons CO: 50 valence electrons
Total: 8 + 50 = 58 valence electrons
Therefore, Fe(CO)5 has a total of 58 valence electrons, not 18 or 16 as mentioned previously. I apologize for the error and any confusion it may have caused.