Periodic Trends • For each slide with a periodic table - copy the definition. Copy ALL of the other slides. • The purpose of this exercise is for you to be able to understand 4 periodic trends and how to predict them. • You will need to know the definitions of the trends and be able to tell me whether two atoms are bigger are smaller, or have more ionization energy, etc. (memorize the diagram with the arrows) • Place the icons at the right over the numbers indicated by the range below the icon. Bonding • More will be explained about bonding later… for now you need to know: – Covalent bonds = sharing electrons – Ionic bonds = stealing electrons H 13.6 If atoms love their electrons it will cost you a lot of energy to steal 1 of them. He 24.6 Li 5.4 Be 9.3 B 8.3 C 11.3 N 14.5 O 13.6 F 17.4 Ne 21.6 Na 5.1 Mg 7.6 Al 6 Si 8.2 P 10.5 S 10.4 Cl 13 Ar 15.8 17-25 12.1-16.9 K 4.3 Ca 6.1 Ga 6 Ge 7.9 As 9.8 Se 9.8 Br 11.8 Kr 14 Rb 4.2 Sr 5.7 In 5.8 Sn 7.3 Sb 8.6 Te 9 I 10.5 Xe 12.1 8.6-12 Cs 3.9 Ba 5.2 Tl 6.1 Pb 7.4 Bi 7.3 Po 8.4 At 9.3 Rn 10.7 6-8.5 Fr 4.1 Ra 5.3 1st Ionization Energy 3.9-5.8 1st Ionization Energy He 24.6 Fr 4.1 Helium loves its electrons because it is full and small. The closer to the right = the closer to fullness = love for electrons. Large elements have a hard time holding electrons. It would cost you a lot of energy to steal an electron from Helium. Francium would be easy to steal from. H 2.2 How strongly atoms attract electrons to themselves when bonding. He Li .98 Be 1.57 B 2.04 C 2.55 N 3.04 O 3.44 F 3.96 Ne Na .93 Mg 1.31 Al 1.61 Si 1.9 P 2.1 S 2.5 Cl 3.16 Ar 3.9-4 3.01-3.89 K .82 Ca 1 Ga 1.81 Ge 2.01 As 2.18 Se 2.55 Br 2.96 Kr Rb .82 Sr .95 In 1.78 Sn 1.96 Sb 2.05 Te 2.1 I 2.66 Xe 2.01-3 Cs .79 Ba .89 Tl 1.8 Pb 1.9 Bi 1.9 Po 2 At 2.2 Rn 1.01-2 Fr .7 Ra .9 Electronegativity 0-1 Electronegativity F 3.96 Fr .7 Small elements can attract electrons more easily because their positive nucleus is closer. Elements on the right want more electrons until the last Group because they are full. Noble gases like Helium is therefore unreactive. Fluorine attracts electrons the most and Francium the least. H 37 Atoms get bigger as you go down and to the left. He 31 Li 152 Be 112 B 85 C 77 N 75 O 73 F 72 Ne 71 Na 186 Mg 160 Al 143 Si 118 P 110 S 103 Cl 100 Ar 98 K 227 Ca 197 Ga 135 Ge 122 As 120 Se 119 Br 114 Kr 112 Rb 248 Sr 215 In 167 Sn 140 Sb 140 Te 142 I 133 Xe 131 Cs 265 Ba 215 Tl 170 Pb 146 Bi 150 Po 168 At 140 Rn 140 Fr 282 Ra 223 Atomic Radii 31-80 81-100 101-159 160-269 270-300 Atomic Radii He 31 Fr 282 Helium is the smallest because it has the least energy levels and is farthest to the right Francium is big because it has the most energy levels and is farthest to the left. H Ions are atoms that have gained or lost electrons. Their size depends on how big they were and whether or not they have gained or lost electrons. He Li 76 Be 31 B 20 C 15 N 146 O 140 F 133 Ne Na 102 Mg 72 Al 54 Si 41 P 212 S 184 Cl 181 Ar 15-40 61-100 K 138 Ca 100 Ga 62 Ge 53 As 222 Se 198 Br 195 Kr Rb 152 Sr 118 In 81 Sn 71 Sb 62 Te 221 I 220 Xe Cs 167 Ba 135 Tl 95 Pb 84 Bi 74 Po At Fr 194 Ra Ionic Radii 41-60 101-170 Rn 171-200 Ionic Radii He C 15 As 222 Fr 194 The left side loses electrons and the right side gains electrons. Carbon is the smallest and looses the most, so its ion is the smallest. As you go down and to the left toward Francium, it gets bigger. It continues to get bigger from the top right down and to the left toward Arsenic which is the biggest. Noble Gases don’t make ions. Questions Copy the following and paste it on a wiki titled 10-1 Periodic Trends. Answer the questions there. ATOMIC RADIUS - Rank the following from smallest to largest atomic radius. 1. Li, C, F 2. Li, Na, K 3. Ge, P, O 4. C, N, Al 5. Al, Cl, Ga 6. Describe the periodic trend IONIC RADIUS - Rank the following from smallest to largest ionic radius. 7. Mg2+, Si4-, S28. Mg2+, Ca2+, Ba2+ 9. F-, Cl-, Br10. Ba2+, Cu2+, Zn2+ 11. Si4-, P3-, O212. Describe the periodic trend IONIZATION ENERGY - Rank the following from lowest to highest ionization energy. 13. Mg, Si, S 14. Mg, Ca, Ba 15. F, Cl, Br 16. Ba, Cu, Ne 17. e. Si, P, He 18. Describe the periodic trend ELECTRONEGATIVITY - Rank the following from lowest to highest electronegativity 19. Li, C, N 20. C, O, Ne 21. Si, P, O 22. K, Mg, P 23. S, F, He 24. Describe the periodic trend