Certainly! Let's go through the detailed steps to determine which element has the smallest ionization energy (IE) among the given elements.
### Ionization Energy Trend:
- Ionization energy is the energy required to remove an electron from an atom.
- Ionization energy generally increases across a period (from left to right) on the periodic table.
- Ionization energy generally decreases down a group (from top to bottom).
### Given Elements:
```
H
Li Be
Na Mg
He
B C N O F Ne
Al Si P S Cl Ar
```
### Determination:
1. Identify Alkali Metals:
- Alkali metals are located in Group 1 of the periodic table and have the lowest ionization energy in their respective periods.
- Among the listed alkali metals, we have:
- Hydrogen (H)
- Lithium (Li)
- Sodium (Na)
2. Compare Alkali Metals:
- Ionization energy decreases as we move down a group. Therefore:
- Lithium (Li) will have a lower ionization energy than Hydrogen (H).
- Sodium (Na) will have a lower ionization energy than Lithium (Li).
3. Conclusion:
- Since Sodium (Na) is below Lithium (Li) in Group 1, it will have the smallest ionization energy among the alkali metals provided in the list.
Thus, considering the list of elements you provided and the trends of ionization energy:
The element with the smallest ionization energy among the given elements is Lithium (Li).
