Which of the following has the higher ionization energy and why: Li or Ba?

I cannot figure this out because they are in different periods but Ba is down on the periodic table telling me that it may have a higher ionization than Li. Help please?

I don't know that there is a way of knowing this. However, I would go with the idea that Li is so small and Ba so large that Ba has a smaller IP than Li. The electron for Ba is so far away from the nucleus it should be easier to pull it off when compared to Li whose outside electron is so close to the nucleus. You know most small periodic charts have a wealth of information on them. Mine lists the first IP of each element and shows Li as 5.39 and Ba as 5.21. Very close.

Thank you so much, this was extremely helpful for me to understand.

To determine which element, Li (Lithium) or Ba (Barium), has a higher ionization energy, we need to understand what ionization energy is and how it varies across the periodic table.

Ionization energy is the amount of energy required to remove an electron from an atom or ion in its gaseous state. It is typically measured in units of kilojoules per mole (kJ/mol). The general trend for ionization energy is as follows:

1. As you move from left to right across a period in the periodic table, ionization energy generally increases.
2. As you move from top to bottom down a group in the periodic table, ionization energy generally decreases.

Applying this knowledge to our comparison of Li and Ba:

- Li is located in Group 1 (Alkali Metals) and Period 2 of the periodic table.
- Ba is located in Group 2 (Alkaline Earth Metals) and Period 6 of the periodic table.

Since Li is on the far left side of the periodic table (Group 1), closer to the noble gases with a fully-filled electron shell, it has a lower ionization energy. On the other hand, Ba is located further to the right (Group 2) and has a higher ionization energy compared to Li.

Therefore, Ba has a higher ionization energy than Li because Ba is further to the right on the periodic table, requiring more energy to remove an electron.

Remember, this is a general trend, and there may be exceptions due to other factors such as electron configuration and shielding effects, but in most cases, this trend holds true.

If you want to find the actual values or more precise information about ionization energy differences between Li and Ba, you can look up their respective ionization energy values in a reliable reference book or use online resources such as the NIST (National Institute of Standards and Technology) database.