1. 3:00 2:59 2:58 2:57 2:56 2:55 2:54 2:53 2:52 2:51 2:50 2:49 2:48 2:47 2:46 2:45 2:44 2:43 2:42 2:41 2:40 2:39 2:38 2:37 2:36 2:35 2:34 2:33 2:32 2:31 2:30 2:29 2:28 2:27 2:26 2:25 2:24 2:23 2:22 2:21 2:20 2:19 2:18 2:17 2:16 2:15 2:14 2:13 2:12 2:11 2:10 2:09 2:08 2:07 2:06 2:05 2:04 2:03 2:02 2:01 2:00 1:59 1:58 1:57 1:56 1:55 1:54 1:53 1:52 1:51 1:50 1:49 1:48 1:47 1:46 1:45 1:44 1:43 1:42 1:41 1:40 1:39 1:38 1:37 1:36 1:35 1:34 1:33 1:32 1:31 1:30 1:29 1:28 1:27 1:26 1:25 1:24 1:23 1:22 1:21 1:20 1:19 1:18 1:17 1:16 1:15 1:14 1:13 1:12 1:11 1:10 1:09 1:08 1:07 1:06 1:05 1:04 1:03 1:02 1:01 1:00 0:59 0:58 0:57 0:56 0:55 0:54 0:53 0:52 0:51 0:50 0:49 0:48 0:47 0:46 0:45 0:44 0:43 0:42 0:41 0:40 0:39 0:38 0:37 0:36 0:35 0:34 0:33 0:32 0:31 0:30 0:29 0:28 0:27 0:26 0:25 0:24 0:23 0:22 0:21 0:20 0:19 0:18 0:17 0:16 0:15 0:14 0:13 0:12 0:11 0:10 0:09 0:08 0:07 0:06 0:05 0:04 0:03 0:02 0:01 0:00 Do Now Name one element that has similar chemical properties to calcium and why they are chemically similar. Any element in the same group is chemically similar because it would have the same number of valence electrons.

2. Trends in the Periodic Table

3. Influenced by three factors 1. Energy Level A higher energy level is further away. 2. Charge on nucleus (# protons) More charge pulls electrons in closer. 3. Shielding effect (a blocking effect?)

4. #1. Atomic Size - Group trends As we go down a group: each atom has another energy level, so the atoms get bigger. H Li Na K Rb

5. #1. Atomic Size - Period Trends Going from left to right across a period, the size gets smaller. Electrons are in the same energy level. But, there is more nuclear charge. Outermost electrons are pulled closer. NaMgAlSiPSClAr

6. Atomic Number Atomic Radius (pm) H Li Ne Ar 10 Na K Kr Rb 3 Period 2

7. Atomic size increases in these directions:

8. #2. Trends in Ionization Energy Ionization energy is the amount of energy required to completely remove an electron to form an ion. Removing one electron makes a 1+ ion. The energy required to remove only the first electron is called the first ionization energy.

9. Ionization Energy The second ionization energy is the energy required to remove the second electron. Always greater than first IE. The third IE is the energy required to remove a third electron. Greater than 1st or 2nd IE.

10. SymbolFirstSecond Third H He Li Be B C N O F Ne 1312 2731 520 900 800 1086 1402 1314 1681 2080 5247 7297 1757 2430 2352 2857 3391 3375 3963 11810 14840 3569 4619 4577 5301 6045 6276

11. What factors determine IE The greater the nuclear charge, the greater IE. Greater distance from nucleus decreases IE

12. Shielding The electron on the outermost energy level has to look through all the other energy levels to see the nucleus. Second electron has same shielding, if it is in the same period

13. Ionization Energy - Group trends As you go down a group, the first IE decreases because... The electron is further away from the attraction of the nucleus There is more shielding.

14. Ionization Energy - Period trends All the atoms in the same period have the same energy level. Same shielding. But, increasing nuclear charge So IE generally increases from left to right.

15. First Ionization energy Atomic number He He has a greater IE than H. Both elements have the same shielding since electrons are only in the first level But He has a greater nuclear charge H

16. First Ionization energy Atomic number H He Li has lower IE than H more shielding further away l These outweigh the greater nuclear charge Li

17. First Ionization energy Atomic number H He Li Be B C N O F Ne Na

18. 3:00 2:59 2:58 2:57 2:56 2:55 2:54 2:53 2:52 2:51 2:50 2:49 2:48 2:47 2:46 2:45 2:44 2:43 2:42 2:41 2:40 2:39 2:38 2:37 2:36 2:35 2:34 2:33 2:32 2:31 2:30 2:29 2:28 2:27 2:26 2:25 2:24 2:23 2:22 2:21 2:20 2:19 2:18 2:17 2:16 2:15 2:14 2:13 2:12 2:11 2:10 2:09 2:08 2:07 2:06 2:05 2:04 2:03 2:02 2:01 2:00 1:59 1:58 1:57 1:56 1:55 1:54 1:53 1:52 1:51 1:50 1:49 1:48 1:47 1:46 1:45 1:44 1:43 1:42 1:41 1:40 1:39 1:38 1:37 1:36 1:35 1:34 1:33 1:32 1:31 1:30 1:29 1:28 1:27 1:26 1:25 1:24 1:23 1:22 1:21 1:20 1:19 1:18 1:17 1:16 1:15 1:14 1:13 1:12 1:11 1:10 1:09 1:08 1:07 1:06 1:05 1:04 1:03 1:02 1:01 1:00 0:59 0:58 0:57 0:56 0:55 0:54 0:53 0:52 0:51 0:50 0:49 0:48 0:47 0:46 0:45 0:44 0:43 0:42 0:41 0:40 0:39 0:38 0:37 0:36 0:35 0:34 0:33 0:32 0:31 0:30 0:29 0:28 0:27 0:26 0:25 0:24 0:23 0:22 0:21 0:20 0:19 0:18 0:17 0:16 0:15 0:14 0:13 0:12 0:11 0:10 0:09 0:08 0:07 0:06 0:05 0:04 0:03 0:02 0:01 0:00 Do Now Which atom is larger and why: Ca or Ba Which atom has a higher ionization energy and why: Na or Fr

19. #3. Trends in Electronegativity Electronegativity is the tendency for an atom to attract electrons to itself when it is chemically combined with another element. They share the electron, sometimes it’s not equal sharing. An element with a large electronegativity pulls electrons toward itself strongly!

20. Electronegativity Group Trend Down a group Electrons are farther from the nucleus More electrons cause shielding, Atoms are more willing to share electrons. Low electronegativity.

21. Electronegativity Period Trend Metals On the left of the table. They let their electrons go easily low electronegativity Nonmetals At the right end of the PT They want more electrons. They try to take them away from others High electronegativity.

22. The arrows indicate the trend: Ionization energy and Electronegativity INCREASE in these directions