1 / 40

Understanding the Periodic Table: Trends and Elements

Learn about the history of the periodic table, how elements are arranged, and the properties of different groups. Explore the periodic trends and characteristics of metals, non-metals, and metalloids.

srumfelt
Download Presentation

Understanding the Periodic Table: Trends and Elements

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Next week…. • Monday: Lab 11 Periodic Trends • Tuesday: Lab 11 Analysis and Intro to Trends • Wednesday: Trends Continued • Thursday: Graded Trends Activity (Due Jan 4th) • Friday: NO SCHOOL

  2. Essential Question • How is the periodic table arranged?

  3. Story time!!!!!!

  4. Dobereiner—Triad Model (1829) Elements in groups of 3 Could not incorporate new elements Newlands—Law of Octaves (1864) Repeating pattern every 8 elements Several known elements didn’t fit the trend History of the P.T.

  5. Mendeleev (1869) • Father of the Periodic Table • Elements’ properties are periodic functions of their atomic mass • Grouped elements based on properties • Left space for “new” elements • Predicted properties of unknown elements

  6. Mendeleev’s Table

  7. Vertically intoGroups/Families Horizontally IntoPeriods Elements are arranged:

  8. Why?

  9. If you looked at one atom of every element in a group/family you would see…

  10. Each atom has the same number of valence electrons -Electrons in the outermost shell - We call these “bonding” electrons

  11. The group 2 atoms all have 2 electrons in their outer shells Be (Beryllium) Atom Mg (Magnesium) Atom

  12. Octet Rule • An atom is most stable with _____ electrons in the outer most energy level • Atoms either gain or lose electrons to achieve this.

  13. The number of outer or “valence” electrons in an atom affects the way an atom bonds. • The way an atom bonds determines many properties of the element. • This is why elements within a group usually have similar properties.

  14. If you looked at an atom from each element in a period you would see…

  15. Each atom has the same number of electron energy levels. An example…

  16. The period 4 atoms each have 4 electronenergy levels 4th Shell K (Potassium) Atom Kr (Krypton) Atom Fe (Iron) Atom

  17. Divisions of the Table • Divided into regions based on general properties • Include: • Metals • Non-metals • Metalloids

  18. Metals • Left of stairstep line • Very dense • Shiny • Solids, high melting pt. • Thermal & electrical conductors • Form + ions

  19. Non-metals • Right of stairstep line • Low density, usually gases • Melt at low temperatures • Do NOT conduct heat or electricity

  20. Metalloids • Have properties of both metals and non-metals • Lie along the stairstep line separating metals and nonmetals • Except Al and Po • Semi-conductors

  21. What are semiconductors used in?

  22. Quick Check! • State whether the following are metals, nonmetals, or metalloids: • Potassium • Iodine • Antimony

  23. Group Properties • The Periodic Table is divided into several groups based on the properties of different atoms.

  24. Review • What group is phosphorus in? • What period is phosphorus in? • How many valence electrons does phosphorus have? • Is it a metal, nonmetal, or metalloid? • How many electrons does it need to gain to be stable?

  25. http://www.lyon.edu/webdata/Users/DMcDowell/GenChem/alkalishow.htmlhttp://www.lyon.edu/webdata/Users/DMcDowell/GenChem/alkalishow.html Alkali Metals

  26. Alkali Metals • Group 1 • Soft, silvery colored metals • 1 valence e- • Form +1 ions • Very reactive!!! • Sodium Drop: http://www.youtube.com/watch?v=MTcgo46nxNE • http://www.youtube.com/watch?v=m55kgyApYrY

  27. Alkaline Earth Metals

  28. Alkaline Earth Metals • Group 2 • Silvery-white metals • 2 valence e- • Form +2 ions • Fairly reactive • Found in rocks in the earth’s crust

  29. Transition Metals

  30. Transition Metals • Have very similar properties • Most are conductors • Malleable/Ductile • Can form multiple ions • Fe can be 2+ or 3+

  31. Lanthanide Series Actinide Series

  32. Rare Earth Metals • Very Reactive • Strongly paramagnetic • Many are radioactive

  33. Halogens

  34. Halogens • Group 17 • Most are poisonous • Gain an e- to form -1 ions • Cl2 was used as a chemical weapon during WWI and WWII

  35. Noble Gases

  36. Noble Gases • Group 18 • Very unreactive • Originally believed to be inert (unreactive) • Gases at room temperature • Helium has the lowest boiling pt (-268.9oC)

  37. Summing It Up • State which group each of the following elements belongs to and give a property of the element. • Lithium • Chlorine • Uranium • Krypton • Strontium • Chromium

More Related