1. HW 8-15 Ionization Energy How much energy is required to remove an electron from an atom?

2. Ionization Energy (IE) ~ the energy required to remove an e-

3. What patterns do you notice across periods and down groups?

4. Ionization Energy

5. Compare ionization energy and atomic radius graphs
Compare ionization energy and atomic radius graphs. What is the relationship between the graphs? How can you explain these connections?

6. Ionization Energy (IE) ~ the energy required to remove an e-
Across a period, ionization energy increases. Reason: Smaller atoms hold electrons more tightly (e- are closer to the nucleus).

7. Ionization Energy (IE) ~ the energy required to remove an e-
Down a group, ionization energy decreases. Reason: Valence e- in larger atoms are farther from the nucleus. (e- are not as strongly attracted to nucleus).

8. Identify Highest I.E.
1) Cs, K, Li Answer: Li > K > Cs Reason: Down a family, radius ↑, I.E. ↓ 2) Ba, Sr, Ca Answer: Ca > Sr > Ba Reason: Down a family, radius ↑, .I.E. ↓

9. Identify Highest I.E. 1) I, Br, Cl Answer: Cl > Br > I
Reason: Down a family, radius ↑, I.E. ↓
2) Mg, Si, S
Answer: Mg > Si > S
Reason: Across a period, radius ↓, .I.E. ↑