Increasing Ionization Energy (IE) and Non-Metallic Character of Elements: N, P, O, and S

Introduction:
The ionization energy (IE) of an element refers to the energy required to remove an electron from an atom or ion in its gaseous state. Non-metallic character refers to the tendency of an element to gain electrons and form negative ions. In this question, we need to arrange the elements N, P, O, and S in order of increasing ionization energy and increasing non-metallic character.

Increasing Ionization Energy (IE):
Ionization energy generally increases across periods from left to right in the periodic table. This is due to the increased effective nuclear charge as the number of protons in the nucleus increases. The greater the nuclear charge, the stronger the attraction between the nucleus and the valence electrons, making it more difficult to remove an electron.

Increasing Non-Metallic Character:
Non-metallic character generally increases across periods from left to right in the periodic table. Non-metals have a greater tendency to gain electrons and form negative ions compared to metals. This is because non-metals have a higher effective nuclear charge and a stronger attraction for electrons. As we move from left to right across a period, the atomic size decreases, leading to a stronger attraction for electrons and an increased non-metallic character.

Arranging the Elements:
To arrange the elements N, P, O, and S in order of increasing ionization energy and increasing non-metallic character, we need to analyze their positions in the periodic table.

1. Nitrogen (N):
- Nitrogen is located to the right of carbon in Group 15, Period 2.
- Nitrogen has a smaller atomic size compared to phosphorus, oxygen, and sulfur.
- Therefore, nitrogen has a higher ionization energy and a greater non-metallic character compared to the other elements.

2. Phosphorus (P):
- Phosphorus is located below nitrogen in Group 15, Period 3.
- Phosphorus has a larger atomic size compared to nitrogen but smaller than oxygen and sulfur.
- Therefore, phosphorus has a lower ionization energy and a lesser non-metallic character compared to nitrogen but higher than oxygen and sulfur.

3. Oxygen (O):
- Oxygen is located to the right of nitrogen in Group 16, Period 2.
- Oxygen has a smaller atomic size compared to sulfur.
- Therefore, oxygen has a higher ionization energy and a greater non-metallic character compared to sulfur.

4. Sulfur (S):
- Sulfur is located below oxygen in Group 16, Period 3.
- Sulfur has a larger atomic size compared to oxygen.
- Therefore, sulfur has a lower ionization energy and a lesser non-metallic character compared to oxygen.

Summary:
Based on the analysis, we can arrange the elements N, P, O, and S in the following order:
1. Nitrogen (N) - highest ionization energy and non-metallic character
2. Phosphorus (P)
3. Oxygen (O)
4. Sulfur (S) - lowest ionization energy and non-metallic character.