The Periodic Table

1. The Periodic Table Unit II—Part 4 Adapted by NCDPI – Unit 2 Matter all around us

2. The Father of the Periodic Table—Dimitri Mendeleev • Mendeleev was the first scientist to notice the relationship between the elements • Arranged his periodic table by atomic mass • Said properties of unknown elements could be predicted by the properties of elements around the missing element Image taken from: http://jscms.jrn.columbia.edu/cns/2006-04-18/fido-luxuriantflowinghair/mendeleev

3. Henry Moseley • Moseley later discovered that the periodic nature of the elements was associated with atomic number, not atomic mass • Image taken from: • http://dewey.library.upenn.edu/sceti/smith/

4. The Periodic Table Column = Group or Family 18 columns on the Periodic Table Row = Period 7 rows on the Periodic Table

5. Periods •Each row is called a “period” •The elements in each period have the same number of energy levels 1st Period = 1 E. Level 2nd Period = 2 E. Levels 3rd Period = 3 E. Levels 4th Period = 4 E. Levels 5th Period = 5 E. Levels 6th Period = 6 E. Levels 7th Period = 7 E. Levels Middle School Science Image: Chem4kids.com

6. Groups •Each column is called a “group” •Each element in a group has the same number of electrons in their outermost energy level (valence electrons) Except for He, it has 2 electrons Group 1 = 1 electron Group 2 = 2 electrons 4 Group 8 = 8 electrons Middle School Science Image: Chem4kids.com

7. Metals, Nonmetals, and Semi-metals Only nonmetal on the metal side Nonmetals are on the right of the stair-step Metals are to the left of the stair- step Semi-metals, “metalloids,” touch the stair-step

8. Special Rows on the PT Lanthanides Actinides

9. What does the information in the box tell me? 1 H 1.008 Atomic Number = # of protons Elemental Symbol Atomic Mass = # of protons plus neutrons

10. 1 H 1.008 3 Li 6.941 + 11 Na 22.990 + + - 19 K 39.098 - - + 37 Rb 85.468 - - + + + + 55 Cs 132.905 + - - + + 87 Fr (223) - - - - The Groups of the Periodic Table • Group 1: The Alkali Metals • Most reactive metals on the PT • Rarely found free in nature • Charge of 1—1 valence electron

11. The Groups of the Periodic Table • Group 2: The Alkaline Earth Metals • Still quite reactive • Charge of 2—2 valence electrons Image: Chem4kids.com Image: http://wildeboer-fitch.wikispaces.com/2008fall+Calcium

12. T he Groups of the Periodic Table • Groups 3-12: Transition Metals • Found freely and in compounds in nature • Charge is usually 2 but can vary—usually 2 valence electrons • Group 13: Boron Family • Charge is 3—3 valence electrons https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcTOt9q27_Eou8z7JNLK7Q33g1oW5nLuZ468bup9AzxryqyuAaV_dA

13. The Groups of the Periodic Table • Group 14: The Carbon Family • Contains elements that can form unusual bonds (carbon and silicon) • Charge is +4 or -4—contains 4 valence electrons • Group 15: The Nitrogen Family • Charge is -3—contains 5 valence electrons

14. The Groups of the Periodic Table • Group 16: The Oxygen Family • Also known as the chalcogens • Charge is -2 has 6 valence electrons • Group 17: The Halogens • Most reactive nonmetals • charge is -1 has 7 valence electrons • Group 18: The Noble Gases (The Inert Gases) • Nonreactive • Charge is 0—2 or 8 valence electrons • https://www.google.come/search?q=valence+electrons+periodic+table