1 3 4 11 12 Organizing the Elements Lesson 3:2 2 5 6 7 8 9 10 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 104 105 106 107 108 109 58 59 60 61 62 63 64 65 66 67 68 69 70 71 90 91 92 93 94 95 96 97 98 99 100 101 102 103 Periodic table blank What did Mendeleev discover? What information does the periodic table contain? How is the periodic table useful? Nov 10 10:31 AM 1
What did Mendeleev discover? Dmitri Mendeleev 1869 Russian Chemist credited with creating first version of the Periodic Table at that time only 63 elements had been discovered few gases 2 liquids mostly solids Mendeleev discovered a pattern that applied to all elements Nov 10 10:33 AM Mendeleev's work Knew some elements had similar chemical and physical properties ex. copper and silver= shiny metals Similarities were an important clue to hidden patterns To find the patterns, he put the elements melting point, density, color and atomic mass on individual cards Mendeleev tried arranging cards in different ways Nov 10 10:39 AM 2
Noticed the pattern of properties appeared when he arranged the elements in order of increasing atomic mass He found properties repeated regularly ex. Li, Na, K = reactive He lined up the cards to form groups that shared similar characteristics Nov 10 10:43 AM Periodic Table Mendeleev created the first periodic table Periodic table is an arrangement of elements showing the repeating pattern of their properties periodic= " in regular, repeating pattern" Mendeleev table had gaps but predicted blank spaces would be filled in by elements as they were discovered. Nov 10 10:46 AM 3
As scientists discovered new elements and learned more about atomic structure, the table changed. Number of protons determines chemical properties better Modern tables are arranged by atomic number (Henry Mosley British chemist came up with that idea) Nov 10 10:50 AM What information does the Periodic Table contain Periodic Table contains information about known elements The Periodic Table is this book contains: Atomic Number number of protons Chemical Symbol one or two letters ( abbreviation of Latin or English names) Atomic Mass average of all isotopes Other tables may include state of matter valence number energy levels/rings Nov 10 11:25 AM 4
How is the Periodic Table useful An element's properties can be predicted from its location on the periodic table atomic number increases let to right colors correspond to classes metals, nonmetals and metalloids properties change in a predictable pattern Nov 10 11:33 AM Periods The table is arranged in rows called periods series of different elements properties change in a pattern metals on the left nonmetals on the right metalloids in between Nov 11 1:03 PM 5
Groups Modern table has 7 periods and 18 columns Columns form groups numbered left to right Elements in each group have similar characteristics Group 1 metals, very reactive with water Group 17 nonmetals very reactive with group 1 Group 18 nonmetals non reactive Nov 11 1:05 PM Lesson 3 2 Organizing the Elements Mendeleev noticed a pattern of properties in elements arranged by atomic mass The Periodic Table includes each element's atomic number, name, chemical symbol, and atomic mass The property of a element can be predicted by its location in the Periodic Table Nov 11 1:08 PM 6