Periodic Table

2. Physical Science Periodic Table

3. Early Attempts • In the 1800’s, chemists tried to organize the elements using their chemical and physical properties • They laid the foundation for the modern periodic table • Some chemists notices that certain properties repeated every eighth element, but this only worked for the first twenty elements • Early tables organized the elements by their atomic mass, this presented some issues with elements such as • Ar and K • Co and Ni • Te and I • Th and Pa • By the early 1900’s the table was arranged in order of Atomic Number rather than mass, the way it is today

4. B) Dmitri Mendeleev • Father of the Periodic Table • Published in 1869 a table with the elements arranged by atomic mass • Left gaps for elements that had not been discovered yet • Because his predictions about unknown elements were so darn close, he is credited with the creation of the periodic table

5. Predictions About the Undiscovered Element- Germanium

6. Sculpture of Mendeleev in Slovakia- Talk about getting your Nerd On!!!!!

7. C) Periodic Table Geography • Horizontal Rows on the table are called Periods • Periods represent energy levels in an atom • Vertical Columns on the table are called Families or Groups • Each element in a family has the same number of valence electrons • Elements in a group have similar chemical and physical properties Periodic Law- says that when arranged by atomic number that certain traits occur periodically, thus creating families, certain family have particular names

8. Group 1 – Alkali Metals * highly reactive metals that do not occur freely in nature -must be stored either in wax or oil to protect * 1 valence electron in the outermost shell * often soft metals, but are good conductors of electricity and heat *malleable and ductile *low melting points *form very strong basic solutions Group 2- Akaline Earth Metals *also highly reactive metals * 2 valence electrons in the outermost shell * called earth metals because of their extremely high melting points *burn reddish colors in flame tests

9. Groups 3-12 Transition Metals *38 elements total *Good conductors, malleable and ductile * these elements the gain or lose electrons differently based upon the particular chemical reaction

10. Group 17 –Halogens *non-metallic *seven valence electrons *elements are found in three different phases-solids, liquids and gas *highly reactive, found in lots of compounds

11. Group 18 – Noble Gases *not very reactive *8 valence electrons in outermost shell, making them stable *all of them are gasses

12. Groups 14-16 – Non-metals also include groups 17-18 *Poor conductors of heat and electricity *very brittle, dull colored *can be solids or liquids *tend to form acidic solutions *lower densities than metals *are highly electronegative, tend to steal electrons from other atoms Metalloids – line the transition between metals and non-metals *have properties similar to both metals and non-metals *elements 5, 14, 32, 33, 51, 52, 84, 85

13. Rare Earth Elements * compose the lanthanide and actinide series -the two lonely rows at the bottom *total of 30 elements *are all metals *most are man-made *highly electrically conductive *mainly formed in complex minerals, which made them seem rare