Understanding the Periodic Table of Elements

1. The Periodic Table Chemistry

2. Do Now – 10/24/2011 • How are elements arranged on the periodic table?

3. Review • Electron Configuration • There are 7 energy levels and corresponding sublevels. • Electrons are arranged in specific ways on energy sublevels. • Sublevels = s,p,d,and f.

4. Periodic Table Brown = S blockRed = P blockYellow = D blockBlue = F block

5. Practice • Ne = 10 electrons 1s2 2s2 2p6 • P = 15 electrons 1s2 2s2 2p6 3s2 3p3 [Ne]10 3s2 3p3 • Ti = 22 electrons 1s2 2s2 2p6 3s2 3p6 4s2 3d2 [Ar]18 4s2 3d2 • Ni = 28 electrons 1s2 2s2 2p6 3s2 3p6 4s2 3d8 [Ar]18 4s2 3d8

6. The Periodic Table • Originally created by Demitri Mendeleev we will cover that tomorrow. • The periodic table is organized into a grid with groups and periods. • Each element is represented by an element box containing the element’s name, symbol, atomic mass, & atomic number.

7. Periods Rows = periods (b/c trends in properties repeat – they’re “periodic” – as you go across the rows)

8. What’s a periodic trend?Here’s an everyday example:

9. Groups/Families Columns = families or groups (b/c they have similar characteristics)

10. The periodic table arranges all the elements in groups according to their properties. Vertical columns are called GROUPS Mendeleev Periodic table Horizontal rows are called PERIODS

11. Learning Check 1 • Which element is in group 1, period 4? A) Be B) Ca C) K D) C

12. Learning Check 2 • Which element is in group 14, period 3? A) Ge B) Na C) C D) Si

13. Parts of the Periodic Table • The periodic table is divided into several sections. • The three main divisions are: Metals Metalloids Non-metals • Within those sections we divide it even further.

14. Metals

15. Metals • On the left (EXCEPT H!) • Metallic properties: • Dense solids • Shiny luster • High melting points • Tend to form positive ions • Good conductors of electricity • Malleable (can stretch into wire) • Ductile (can beat into sheets)

16. Nonmetals

17. Nonmetals • On the right (AND hydrogen!) • Properties: • Low melting points • Low densities • Dull luster • Poor conductors of heat and electricity • Many are gasses at room temperature

18. Semi-metals or Metalloids

19. Metalloids • Touching the stair step (except Al) • To draw stair step: start between B and Al. • Properties of both metals and nonmetals • Good semiconductors

20. Chemical Families • Group 1 (except H!): Alkali metals • Explode in water • Soft • Group 2: Alkaline Earth metals • Very reactive (Less reactive than alkali) • Hard (why they’re called “Earth” metals) • Groups 3 -12: Transition metals • Group 17: Halogens • Very reactive • Group 18: Noble gasses • Inert (don’t react)

21. Alkali Metals – Group 1A • Soft metals, cut it with knife • Highly reactive • Good conductors of heat and electricity

22. Alkaline Earth Metals – Group 2A • Shiny solids, harder than Alkali metals • Less reactive than Alkali Metals • React with oxygen • Doesn't dissolve easily in water

23. Halogens – Group 7A • Very reactive nonmetals • Always found combined with other elements in nature

24. Transition metals • Good Electrical Conductors • The greater the hardness of the metal the higher the melting points • Lustrous • Malleable

25. Inner Transition Metals • Divided into Lanthanides (top) & Actinide (bottom) • Lanthanides – silvery, high melting pts • Actinides - radioactive elements • Only three actinides exist in nature

26. Noble Gases – Group 8A • Last natural elements to be discovered • Colorless • Unreactive • Very Stable