3. Periodic Table

5. (1) http://www.facts-about.org.uk/science-element-magnesium.htm

22. Copper (9000 B.C) Iron (4000 B.C) Aluminium (1825) Magnesium (1808) Potassium (1807) Zinc (1746)

23. http://www.youtube.com/watch?v=eCk0lYB_8c0

25. Bibliography: http://www.facts-about.org.uk/science-element-magnesium.htm http://chemistry.about.com/od/elementfacts/a/magnesium.htm http://www.facts-about.org.uk/science-element-zinc.htm http://www.webelements.com/zinc/ http://www.webelements.com/copper/ http://www.chemguide.co.uk/inorganic/extraction/copper.html http://www.facts-about.org.uk/science-element-potassium.htm http://www.rsc.org/chemsoc/visualelements/pages/data/potassium_data.html http://www.facts-about.org.uk/science-element-aluminum.htm http://en.wikiversity.org/wiki/Extraction_of_aluminium http://www.facts-about.org.uk/science-element-iron.htm http://www.whoguides.com/who-discovered-iron