Worksheet: Ionization Energy Name ____________________ 1. What is ionization energy? The energy needed to remove an electron from an atom. 2. Which element has the highest ionization energy? Helium 3. Which element has the lowest ionization energy? Francium 4. Rank the following in order from lowest to highest ionization energy? Li, Na, K K < Na < Li 5. Rank the following in order from lowest to highest ionization energy? Na, Mg, Al Na < Mg < Al 6. How does the size of an atom relate to its ionization energy? The larger the atom the lower the ionization energy Or The smaller the atom the higher the ionization energy 7. How does the effective nuclear charge of an atom relate to its ionization energy? The greater the effective nuclear charge the greater the ionization energy Or The lower the effective nuclear charge the lower the ionization energy 8. How many ionization energies does aluminum (Al) have? 13 9. Which of aluminum’s ionization energies is the highest? Why? The 13th Because each time an electron is removed from an atom the remaining electrons are pulled in more tightly and require more energy to remove. 10. What is the fourth ionization energy of aluminum refer to? It is the energy needed to remove an electron after you have already removed three.