To determine the number of valence electrons for each of these atoms, we can look at their positions in the periodic table.
- Nitrogen (Z=7): Nitrogen is located in group 15 of the periodic table, which means it has 5 valence electrons. This is because the number of valence electrons is equal to the group number minus 10 for groups 13-18.
- Chlorine (Z=17): Chlorine is in group 17, indicating it has 7 valence electrons. It tends to gain an electron to achieve a full outer shell, which is the configuration of noble gases.
- Sodium (Z=11): Sodium is found in group 1 and has 1 valence electron. This is typical for alkali metals, which have one electron in their outermost shell.
- Aluminum (Z=13): Aluminum is in group 13, which gives it 3 valence electrons. This means it can lose three electrons to achieve a stable electron configuration.
In summary, the number of valence electrons for each atom is:
- Nitrogen: 5
- Chlorine: 7
- Sodium: 1
- Aluminum: 3