Periodic Trends
1. Match the following: Shielding Effect The decrease of attraction between the nucleus and electrons because of the presence of energy shells Atomic Radius The measure of the distance between radii of two identical atoms of an element Ionization Energy Energy required to remove an electron from an atom Electronegativity The measure of attraction an atom has for electrons in a chemical bond 2. Place the following elements in order of increasing (smallest to largest) atomic radius: B, Ne, Li, N Li, B, N, Ne Ne, N, B, Li 3. Explain why atomic radius increases down a group but decreases across a period. 4. Which element on the periodic table has the largest atomic radius? Fr H He Rn 5. Given the representation of a chlorine atom, which circle might represent an atom of fluorine? Circle B Circle C Circle D 6. Place the following elements in order of decreasing (largest to smallest) electronegativity: Br, Cl, I, F F>Cl>Br>I 7. Place the following elements in order of increasing (smallest to largest) ionization energy: B, N, Li, F Li<B<N<F 8. Which element on the periodic table has the largest electronegativity? H He F Fr 9. Why do noble gases not have an electronegativity value? 10. The following table shows the electronegativity values for the halogens. State what kind of pattern exists. 11. Which element has the lower ionization energy, rubidium or iodine? rubidium iodine 12. Zeff = Z – S is the formula for effective nuclear force. What does the Z represent? The S? Z represents the number of valence electrons S is the number of shielding electrons. Z is the number of protons and S is the number of non-valence electrons. Z represents the number of neutrons and S represents the number of valence electrons 14. Which one has a larger radius? Mg Mg2+ 15. Which one has a larger radius? F- Cl- 16. Which one has a larger radius? Mg2+ Na+ 17. Ionization Energy The ionization energy is the amount of energy needed to remove an electron from an atom. Which do you think takes more energy, removing an electron from an atom where the nucleus has a tight hold on its electrons, or a weak hold on its electrons? Explain. 18. Ionization Energy Atoms with loosely held electrons are usually classified as metals. They will exhibit high conductivity, ductility, and malleability because of their atomic structure. Would you expect metals to have high ionization energies or low ionization energies? Explain your answer in one to two complete sentences. (Think about how you answered question #17.) 19. Which trend(s) does the following diagram represent? atomic radius ionization energy electronegativity shielding 20. Which trend(s) does the following diagram represent? atomic radius ionization energy electronegativity shielding