Presentation on theme: "Organizing the Elements. 1.What practice by chemists increased the rate of discovery of the elements? Chemist began investigating materials in a systematic."— Presentation transcript:
Organizing the Elements
1.What practice by chemists increased the rate of discovery of the elements? Chemist began investigating materials in a systematic way: The Scientific Method of Inquiry
2.How did Levoisier group the elements? Levoisier grouped the known elements into metals, nonmetals, gases and earths.
3.How is the game of solitaire related to the periodic table? Mendeleev was inspired by the game of solitaire to group the elements in order of increasing mass. In doing this a pattern emerged and elements with similar properties were grouped in the same column. Columns are organized by properties instead of suits.
4.How did Mendeleev arrange the elements in the periodic table? Mendeleev grouped the elements into rows in order of increasing mass so that elements with similar properties were in the same column. A periodic table is an arrangement of elements in columns, based on a set of properties that repeat from row to row.
5.At quick glance of the Mendeleev’s periodic table (bottom of page 127), what are some differences you spot from the modern periodic table (like the one on the wall or in your book)? There are blank spots in Mendeleev’s table. Element names are missing from Mendeleev’s table. Two elements can occupy a square in Mendeleev’s table. Others?
6.Why couldn’t Mendeleev make a complete table of the elements? Mendeleev couldn’t make a complete table because many elements had not yet been discovered. Mendeleev left spaces for these undiscovered elements.
7.How did Mendeleev know where to leave spaces in his periodic table? Using the scientific method Mendeleev made predictions about the properties of the undiscovered elements. M. predicted the properties of the element that belonged one space below aluminum: a soft metal with a low melting point and a density of 5.9 g/cm3. (1860s) In 1875 the element Galium was discovered with the predicted properties!
8.How did the discovery of new elements such as gallium demonstrate the usefulness of Mendeleev’s table? The close match between M.s predictions and the actual properties of new elements proved the usefulness of the table.