Chapter 3- Understanding the Periodic Table

1. 7th Grade Chapter 3- Understanding the Periodic Table

2. 7th Grade Science Chapter 3- Understanding the Periodic Table PISD PowerPoint Lessons Developed By Ryan Gross, Park Crest Middle School Edited By Kenn Heydrick, Coordinator of Science & Health

3. Chapter 3 - Understanding the Periodic Table Section 1: Electrons and the Periodic Table Section 2: Grouping the Elements Unit A: Chapter 3

4. Why Do I Need the Periodic Table? What Do You Think? What does your outer shell of clothing say to other people about you and who you are? Unit A: Chapter 3

5. Electrons & the Periodic Table • Electrons in all atoms are arranged around the nucleus in regions called energy levels • The largest atoms have as many as seven energy levels Energy Levels Unit A: Chapter 3

6. Electrons & the Periodic Table The outermost energy level is called the valence shell The electrons in the valence shell are called valence electrons Energy Levels Unit A: Chapter 3

7. Electrons & the Periodic Table Elements are grouped because they have similar properties In some groups, the elements all have the same number of valence electrons in their atoms Unit A: Chapter 3

8. Electrons & the Periodic Table In atoms of elements in Groups 1 & 2, the number of valence electronsmatches the group number Unit A: Chapter 3

9. Electrons & the Periodic Table In atoms of elements in Groups 13-18, the number of valence electrons is10 fewer than the group number Unit A: Chapter 3

10. Electrons & the Periodic Table • Atoms of elements in Groups 3-12, the Transition Metals, do not follow a general rule • In addition, helium atoms only have 2 valence electrons Unit A: Chapter 3

11. Why Do I Need the Periodic Table? What Do You Think? What similarities exist between you and the other members of your family? How about between you and your classmates? Unit A: Chapter 3

12. Grouping the Elements - Group 1 Group 1: Alkali Metals- 1 Valence Electron All metals except Hydrogen, the Group 1 elements, are the most reactive. Unit A: Chapter 3

13. Grouping the Elements - Group 1 Group 1: Alkali Metals- 1 Valence Electron This means that the atoms of these elements are not stable and will lend valence electrons to other atoms. Unit A: Chapter 3

14. Grouping the Elements - Group 1 Group 1: Alkali Metals- 1 Valence Electron These elements are never found uncombined in nature. Unit A: Chapter 3

15. Grouping the Elements - Group 1 Alkali Metals • Compounds formed from Alkali metals have many uses for humans • NaCl, or Sodium Chloride, is table salt that is used to season your food • Potassium compounds are found in bananas Unit A: Chapter 3

16. Grouping the Elements - Group 2 Group 2: Alkaline-Earth Metals- 2 Valence Electrons Alkaline-Earth metals are very reactive, but not as reactive as Alkali metals. Unit A: Chapter 3

17. Grouping the Elements - Group 2 Group 2: Alkaline-Earth Metals- 2 Valence Electrons This is because it is harder for their atoms to lose 2 valence electrons than for the Alkali metals to lose 1 Unit A: Chapter 3

18. Grouping the Elements - Group 2 Group 2: Alkaline Earth Metals • Magnesium is mixed with other metals to make rims on cars. • Calcium is an important part of the compound that keeps your bones and teeth healthy. Unit A: Chapter 3

19. Grouping the ElementsGroups 3-12 Groups 3-12: Transition Metals Groups 3-12 do not have individual names. Unit A: Chapter 3

20. Groups 3-12 Groups 3-12 are all grouped together as the Transition Metals. Groups 3-12 Unit A: Chapter 3

21. Groups 3-12 The Transition Metals are less reactive than Groups 1 & 2 because they don’t lose their valence electrons as easily. Groups 3-12 Unit A: Chapter 3

22. Grouping the Elements Silver and Gold are Transition Metals. Unit A: Chapter 3

23. Grouping the Elements Transition Metals Iron, Cobalt, and Nickel, all Transition Metals, are the only elements known to produce a magnetic field. Unit A: Chapter 3

24. Group 13 Group 13: Boron Group The most common element from Group 13 is aluminum. Unit A: Chapter 3

25. Group 13 • Aluminum was considered more precious than gold or silver until the 1880s, when plentiful electricity made it cheaper. • Aluminum is used to make cans, cars, and airplanes. Unit A: Chapter 3

26. Group 14 Group 14: Carbon Group The nonmetal Carbon, in Group 14, is often found uncombined in nature. Unit A: Chapter 3

27. Group 14 Carbon forms both diamonds and charcoal. Carbon also forms a wide variety of compounds such as proteins, fats, and carbohydrates, all necessary for life on earth. Unit A: Chapter 3

28. Group 15 Group 15: Nitrogen Group Nitrogen, a gas at room temperature, makes up about 78% of the air you breathe. Unit A: Chapter 3

29. Group 15 Group 15: Nitrogen Group Nitrogen from the air is combined with Hydrogen to make fertilizer. Fertilizer helps grow the crops that feed us all. Unit A: Chapter 3

30. Group 16 Oxygen, in Group 16, makes up about 21% of the air you breathe. Oxygen is very reactive, combining with many other elements such as iron and carbon. Unit A: Chapter 3

31. Group 16 • Sulfur, another common member of Group 16, is used to make sulfuric acid for car batteries. Unit A: Chapter 3

32. Group 17 Halogens are the very reactive nonmetals in Group 17. They react easily because their atoms only need to gain 1 electron to have a complete set Unit A: Chapter 3

33. Group 17 Chlorine is a yellow halogen that is used to disinfect water for drinking and swimming Unit A: Chapter 3

34. Group 18 Noble gases are unreactive nonmetals in Group 18. These elements’ atoms have full outermost energy levels, and cannot react with other elements Unit A: Chapter 3

35. Group 18 Noble gases like neon glow when electrically charged. Argon in a light bulb keeps the filament from burning out. Unit A: Chapter 3

36. Let’s Review! • 1 - • How does the periodic table help you identify the physical properties of elements? Unit A: Chapter 3

37. Let’s Review! • 2 - • How are elements grouped on the periodic table of elements? Unit A: Chapter 3