Examples of Elements with High Ionization Energy

🧪 Quick Study Guide

• ⚛️ Ionization energy (IE) is the energy required to remove an electron from a gaseous atom or ion.
• 📈 IE generally increases across a period (left to right) due to increasing effective nuclear charge.
• 📉 IE generally decreases down a group (top to bottom) due to increasing atomic size and shielding.
• Noble gases (He, Ne, Ar, Kr, Xe, Rn) have exceptionally high IE because they have full valence shells, making them very stable.
• Elements with smaller atomic radii and greater nuclear charge tend to have higher IE.
• The first ionization energy ($IE_1$) refers to removing the first electron, the second ionization energy ($IE_2$) refers to removing the second electron, and so on. $IE_2 > IE_1$ because it's harder to remove an electron from a positive ion.
• 🌟 Exceptions exist due to electron configurations (e.g., half-filled and fully-filled subshells provide extra stability).

Practice Quiz

1. Which of the following elements has the highest first ionization energy?
   1. A. Sodium (Na)
   2. B. Potassium (K)
   3. C. Helium (He)
   4. D. Lithium (Li)
2. Which group of elements is characterized by having very high ionization energies?
   1. A. Alkali Metals
   2. B. Alkaline Earth Metals
   3. C. Halogens
   4. D. Noble Gases
3. Why does Helium (He) have a higher ionization energy than Hydrogen (H)?
   1. A. Helium has a smaller nuclear charge.
   2. B. Helium has a larger atomic radius.
   3. C. Helium has a full valence shell, making it more stable.
   4. D. Hydrogen has more electrons.
4. As you move down Group 1 (Alkali Metals), what happens to the ionization energy?
   1. A. Increases
   2. B. Decreases
   3. C. Remains constant
   4. D. Fluctuates randomly
5. Which of the following has the highest second ionization energy?
   1. A. Sodium (Na)
   2. B. Magnesium (Mg)
   3. C. Aluminum (Al)
   4. D. Silicon (Si)
6. Which of the following electronic configurations would likely have the highest ionization energy?
   1. A. $ns^2np^4$
   2. B. $ns^2np^3$
   3. C. $ns^2np^6$
   4. D. $ns^2np^5$
7. Which statement best explains why ionization energy generally increases across a period?
   1. A. The number of electron shells increases.
   2. B. The effective nuclear charge increases.
   3. C. Atomic radius increases.
   4. D. Shielding effect increases.