1. ChemCatalyst  What do you know about the periodic table? Let’s sing along

2. The Periodic Table

3. Why is the Periodic Table important to me?  The periodic table is the most useful tool to a chemist.  It organizes lots of information about all the known elements.

4. Pre-Periodic Table Chemistry  Chemistry was a mess  No organization of elements  Difficult to find information.

5. Dmitri Mendeleev: Father of the Table HOW HIS WORKED  Put elements in rows by increasing atomic weight  Put elements in columns by the way they reacted SOME PROBLEMS  He left blank spaces for what he said were undiscovered elements  He broke the pattern of increasing atomic weight to keep similar reacting elements together

7. The Current Periodic Table  Mendeleev wasn’t too far off  Now the elements are put in rows by increasing ATOMIC NUMBER Atomic number = # protons  The horizontal rows are called periods and are labeled from 1 to 7  The vertical columns are called groups are labeled from 1 to 18

8. Groups  Elements in the same group have similar chemical and physical properties Mendeleev did that on purpose  Why? Hold that thought…

9. Families  Columns are also grouped into families  Families may be one column, or several columns put together.  Families have names rather than numbers Just like families with a common last name

10. Hydrogen  Hydrogen belongs to a family of its own  Hydrogen is a diatomic, reactive gas  Responsible for Hindenburg explosion  Hydrogen is promising as an alternative fuel source for automobiles

11. Alkali Metals  1 st column on the periodic table (Group 1) not including hydrogen.  Very reactive metals, always combined with something else in nature (like in salt) Never found in elemental form  Soft enough to cut with a butter knife  Reactions of Alkali Metals Reactions of Alkali Metals

12. Alkaline Earth Metals  Second column on the periodic table (Group 2)  Reactive metals that are always combined with nonmetals in nature  Several of these elements are important mineral nutrients (such as Mg and Ca)

13. Transition Metals  Elements in groups 3-12  Less reactive harder metals  Includes metals used in jewelry and construction.

14. Chalcogens  Elements in group 16  Oxygen is necessary for respiration.  Many things that stink, contain sulfur (rotten eggs, garlic, skunks, etc)

15. Halogens  Elements in group 17  Very reactive, volatile, diatomic, nonmetals  Always found combined with other elements in nature.  Used as disinfectants and to strengthen teeth.

16. The Noble Gases  Elements in group 18  VERY unreactive, monatomic gases  Used in lighted “neon” signs

17. Lanthanides and Actinides  These are the groups at the bottom of the periodic table.  They are not very common

18. What are the elements at room temperature? IIf you look at the table. The solid colored ones are solid The blue ones are liquid The outlined ones are man-made solids The red ones are gases

19. Metals, Non Metals, Metalloids?

20. Metals  Shiny surface when freshly cleaned or cut  Solid at room temperature (not Hg)  Generally are good conductors of heat and electricity  Can be melted or fused  Can be hammered into thin sheets (malleable) or drawn into wires (ductile)

21. Nonmetals  Elements in groups 14-16 (upper right hand corner)  Greater variation in physical properties than metals  Most are gases at room temperature Some are solids (S, P) Br is liquid  Not able to conduct electricity or heat very well (except C)  Very brittle  Not ductile or malleable

22. Metalloids  Have properties of both metals and non-metals Determined by changing conditions  Reside on heavy stair-step line that separates the metals from non-metals  B, Si, Ge, As, Sb, Te, At  Some of the metalloids, such as silicon and germanium, are semi-conductors Can carry an electrical charge under special conditions. Useful in computers and calculators

24. MY FAVORITES!  University of Nottingham University of Nottingham