CHEM 110 Lecture 6: Chapter 06
1 Oct 2017
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Document Summary
Mendelev, 1869: arranged elements in order of increasing atomic mass, led to natural grouping of elements with similar chemical properties, predicted existence of elements that had yet to be discovered, some inconsistencies. The modern periodic table: elements listed in order of increasing atomic number. Group: a vertical column of elements, contains elements with similar chemical properties. Period: a horizontal row of elements, elements are not related chemically. Metals: lustre, thermal and electrical conductivity, malleability. Metalloids: properties intermediate between those of metals and nonmetals. Note: in this course, we will refer each group by the numbers 1-18 and not by roman numeral numbers. Behavior of an electron: energy of an electron determines its behaviour about the nucleus, energy is quantized therefore electrons can only have certain behaviour , the chemistry of an element arises from its electrons. Electron subshells: an energy sublevel within an electron shell, all electrons in the same subshell have the same energy.
