To determine the total number of valence electrons in the nitrate ion (NO3–), we need to consider the individual contribution of each atom in the ion.
Nitrogen (N) is in group 15 of the periodic table and has 5 valence electrons. Each oxygen (O) atom, which is in group 16, has 6 valence electrons. Since there are three oxygen atoms, they contribute a total of 3 × 6 = 18 valence electrons.
Additionally, since the nitrate ion carries a negative charge (-1), we need to add one extra electron to account for this charge. Therefore, we can calculate the total number of valence electrons as follows:
- Valence electrons from nitrogen: 5
- Valence electrons from three oxygen atoms: 18
- Extra electron due to negative charge: 1
Now, summing these values gives:
Total valence electrons = 5 + 18 + 1 = 24
Hence, the total number of valence electrons in the Lewis structure of the nitrate ion (NO3–) is 24.