📚 Topic Summary
Ionization energy is the energy required to remove an electron from a gaseous atom or ion. Successive ionization energies increase because it becomes progressively harder to remove an electron from a positively charged species. Understanding trends in ionization energy helps predict the reactivity and electronic structure of elements. This worksheet will provide a structured way to test your understanding of ionization energy through vocabulary matching, fill-in-the-blanks, and critical thinking questions.
🧠 Part A: Vocabulary
Match the term with the correct definition:
| Term |
Definition |
| 1. Ionization Energy |
A. The energy change when an electron is added to a gaseous atom. |
| 2. First Ionization Energy |
B. The minimum energy required to remove an electron from a neutral gaseous atom. |
| 3. Second Ionization Energy |
C. The energy required to remove the first electron from a singly charged positive ion. |
| 4. Electron Affinity |
D. The energy required to remove an electron. |
| 5. Core Electrons |
E. Electrons in the inner shells of an atom. |
🧪 Part B: Fill in the Blanks
Complete the following paragraph using the words provided: increases, noble gases, valence, decreases, left, energy.
Ionization _________ generally _________ across a period (from _________ to right) due to increasing nuclear charge and _________ electrons being held more tightly. Ionization energy _________ down a group as the outermost electrons are farther from the nucleus. Elements with high ionization energies are typically _________.
💡 Part C: Critical Thinking
Explain why the second ionization energy of an element is always greater than its first ionization energy.