CHE 106 Lecture Notes - Lecture 24: Effective Nuclear Charge, Atomic Radius, Periodic Trends

6) Calculate the effective nuclear charge for oxygen. (2) 7) True or False (9) Effective nuclear charge is the positive charge experienced by the electron from the nucleus and it increases from left to right across the period a. b. Effective nuclear charge slightly decreases going down a family. c. Atomic radius tends to decrease moving from left to right within a period due to the increasing principal quantum number. Anions are larger than their parent atoms because electrons are added to the valence shell increasing the electron-electron repulsion. d. e. The Zett for chlorine is larger than that of magnesium. f. Mg2* is smaller than Na because Mg2 has an extra electron. g. The ionization energy of Na* is significantly higher Na2 because it takes more energy to remove the inner shell core electrons. Ca, Cr, and Ni are metallic elements because they are on the right side of the periodic table. Sb, Al, and Ar are metalloids (semi-metals) because their properties fall between those of metals and those of non-metals. h. i. Calculate the electronegativity difference (ED) and then classify the bonding as either non-polar covalent (NPC), polar covalent (PC) or ionic (1). Use the electronegativity values from the power point in class. (10) 8) (NPC , PC,I) (NPC , PC,I) (NPC , PC,リ NPC , PC, I) (NPC , PC,I) ED ED a. C-H c. Na-C ED d. F-0 ED ED e. N-C

6) Calculate the effective nuclear charge for oxygen.(2) 7) True or False (9) a. Effective nuclear ch electron from th period arge is the positive charge experienced by the e nucleus and it increases from left to right across the b. Effective nuclear charge slightly decreases going d c. Atomic radius tends to decrease moving from le down a family. to right within a period due to the increasing principal quantum numlectrons are Anions are larger than their parent atoms be added to th . e valence shell increasing the electron-electron repulsion. The Zeff for chlorine is larger than that of magnesium. takes more energy to remove the inner shell core e of the periodic table. e. Smaller than Na' because Mg2 has an extra electron. lectrons. f. Mg2* is g The ionization energy of Na is significantly higher Na because it h. Ca, Cr, i. Sb, and Ni are metallic elements because they are on the right side Al, and Ar are metalloids (semi-metals) because their properties fall between those of metals and those of non-metals. alculate the electronegativity difference (ED) and then classify the bonding as either non-polar covalent (NPC), polar covalent (PC) or ionic (). Use the electronegativity values from the power point in class. (10) 8) C a. C-H b. H-O C. Na-Cl ED ED ED ED(NPC , PC, I) ED (NPC, PC,I) (NPC , PC , -(NPC , PC , I) e.N_CI (NPC , PC , I 〕