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The Periodic Table Of Elements.

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Presentation on theme: "The Periodic Table Of Elements."— Presentation transcript:

1 The Periodic Table Of Elements

2 Development of the Modern Periodic Table
Objectives Trace the development and identify key features of the periodic table Identify specific groups within the periodic table


4 Organizing by Properties
1869 – Dmitri Mendeleev organized known elements into chart (rows and columns) According to atomic mass Similar to putting together a large puzzle Predicted new elements would be discovered with certain properties


6 Arranging by Atomic Number
Many discrepancies with Mendeleev’s table Moseley arranged by increasing atomic number rather than atomic mass Discrepancies disappeared

7 Periodic Law The properties of the elements repeat periodically when the elements are arranged in increasing order by their atomic number.

8 Modern Periodic Table

9 First Ionization Energy
The energy required to remove one electron from an atom in a gaseous phase

10 Periodic Table Today Vertical column = group or family
Horizontal row = period Check out periodic table on wall

11 Chemical Families 1A = alkali metals (react with water to form alkaline, or basic, solution 2Na(s) + 2H2O(l) = 2NaOH(aq) + H2(g) + heat energy 2A = alkaline earth metals also react with water 7A = halogens (salt formers)\ 1A-8A = representative metals Bgroup (2A-3A) = transition metals Two bottom rows = inner transition metals (lanthanides and actinides)

12 Periods 7th period incomplete – fewer than half occur naturally on earth and all are radioactive

13 Classification Cont. Metals – to the left of the staircase
Properties: generally shiny when smooth and clean, solid at room temperature, good conductors of heat and electricity Nonmetals – to the right of the staircase Properties: generally gases or brittle, dull-looking solids. Poor conductors of heat and electricity Metalloids – bordering staircase Si and Ge are most important for use in semiconductors


15 Homework 6.1 assessment P.174 # 26-40
Quarter extra credit (25 points exam) Develop a periodic table (must be large on posterboard) expressing periodicity in an interest you may have

16 Activity In the cards periodic table activity

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