tuesday october 9, 2012 (history of the periodic table; mendeleev; customize your own periodic...
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TuesdayOctober 9, 2012
(History of the Periodic Table; Mendeleev;
Customize Your Own Periodic Table)
Bell RingerTuesday, 10-9-12
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.
Assignment Currently Open
Summative or
Formative?Date Issued Date Due Date Into
GradeSpeed Final Day
Project - History of Atomic Structure
ResearchS 1 & 2 9/27 10/5 10/11
QUIZ 5 S7 9/28 9/28 10/12
QUIZ 6 S3 10/5 10/5 10/19
History of the Periodic Table1860 – 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
Groups and Periods on the Modern Periodic Table.
Vertical columns are called “groups”
There are 18 groups on today’s Periodic Table
1
2
3 etc
18
Groups and Periods on the Modern Periodic Table.
Horizontal rows are called “periods”
There are 7 periods on today’s Periodic Table