Final answer:
The elements in order of increasing ionization energy are: Na, Al, Cl, S, Cs.
Step-by-step explanation:
The ionization energy is defined as the energy required to remove an electron from a gaseous atom or ion. In general, ionization energy increases across a period from left to right and decreases down a group. Let's arrange the elements in order of increasing ionization energy.
- Sodium (Na) - It has the lowest ionization energy because it is in the alkali metal group.
- Aluminum (Al) - It has a higher ionization energy than sodium as it is located to the right of sodium in the periodic table.
- Chlorine (Cl) - It has a higher ionization energy than aluminum as it is located farther to the right, near the noble gases.
- Sulfur (S) - It has a higher ionization energy than chlorine as it is located farther to the right in the periodic table.
- Cesium (Cs) - It has the highest ionization energy as it is a member of the alkali metal group, but the ionization energy is still higher than the previous elements mentioned.