PPT Slide
- In the late 1800's researchers noted recurring, or periodic, patterns of behavior of elements.
- In 1871, the Russian chemist Dmitri Mendeleev created a table of the elements listed by increasing atomic mass.
- He arranged so that elements with similar chemical properties would lie in the same column.
- Medeleev predicted undiscovered elements by observing vacancies in his table.
- He was even able to forecast the properties of the unknown elements from the position of the vacancy.
- A modern version of the periodic table appears in Figure 2.16 and inside the front cover of the text.
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