1. As the first five elements in group 15 are considered in order of increasing atomic number , first ionization energy 1. Decreases
2. Increases
3. Decreases then increases
4. Increases then decreases

2. Based on table S , an atom of which element has the strongest attraction for electrons in a chemical bond ?
1. Aluminum
2.Chlorine
3.Magnesium
4.Sulfur

3. Which element reacts with oxygen to form ionic bonds ?
1.Calcium
2.Hydrogen
3.Chlorine
4.Nitrogen