Tuesday October 9, 2012 (History of the Periodic Table; Mendeleev; Customize Your Own Periodic Table)

Bell Ringer Tuesday, What is the Periodic Table and what is it used for? The Periodic Table is a tabular display of the chemical elements, organized on the basis of their atomic numbers, electron configurations, and recurring chemical properties. Elements are presented in increasing atomic number. Using the periodic trends displayed, the Periodic Table can help predict the properties of various elements and the relations between properties. As a result it provides a useful framework for analyzing chemical behavior, and is widely used in chemistry and other sciences.

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Assignment Currently Open Summative or Formative? Date IssuedDate Due Date Into GradeSpeed Final Day Project - History of Atomic Structure Research S 1 & 29/2710/510/11 QUIZ 5S79/28 10/12 QUIZ 6S310/5 10/19

History of the Periodic Table

1860 – The Beginning of the American Civil War

History of the Periodic Table 1860 – The Beginning of the American Civil War  At this time in history, more than 60 elements had already been discovered, but all of their properties had yet to be learned.  There was no method for determining the atomic mass or the number of atoms of an element in a compound – different masses were being used for the same element!

Mendeleev and Chemical Periodicity  In the late 1860's, Russian chemist Dmitri Mendeleev began working on his great achievement: the Periodic Table of the Elements.  By arranging all of the 63 elements then known by their atomic masses, he managed to organize them into groups possessing similar properties.

Mendeleev and Chemical Periodicity  Where a gap existed in the table, he predicted a new element would one day be found and deduced its properties.  And he was right! Three of those elements were found during his lifetime: gallium, scandium, and germanium. Sc Ga & Ge

Mendeleev and Chemical Periodicity  Mendeleev noticed that when elements were arranged in order of increasing atomic mass, certain similarities in their chemical propertied appeared at regular intervals.  This repeating pattern is referred to as periodic.

 So, in 1869, Mendeleev created a table which grouped elements with similar properties together.  He had created the first Periodic Table! Mendeleev and Chemical Periodicity

Begin Activity Customize Your Own

Groups and Periods on the Modern Periodic Table. Vertical columns are called “groups” There are 18 groups on today’s Periodic Table 1 2 3etc 18

Groups and Periods on the Modern Periodic Table. Horizontal rows are called “periods” There are 7 periods on today’s Periodic Table

The modern Periodic Table is divided into 4 blocks s-block p-blockd-block f-block

The modern Periodic Table contains three different categories of elements. metals non-metals metalloids