Monday, June 4, 2007

Lecture Level I. The Periodic Table

Periodic table was covered in the X class syllabus. But there are some interesting points about the periodic table that were covered in Redmund’s book in 5th chapter.

We all know that the horizontal rows in the periodic table are called periods, and the vertical columns are called groups. The groups are subdivided into A and B subgroups. The A subgroups, due to their similarities within a group, are often called families. Some of these families are referred to by special names, such as the alkali metals for Group IA, alkaline earth metals for Group IIA, and halogens for Group VIIA. The other A subgroups are sometimes classified according to the first member of the subgroup or family. Thus the IIIA elements are sometimes referred to as the boron family, the IVA elements as the carbon family, the VA elements as the nitrogen family, and the VIA elements as the oxygen family. The last group, called Group zero (or sometimes Group VIIIA), is now called the noble gases.

As well as being classified as metals or nonmetals, the elements are also divided into the following four types: representative elements, noble gases, transition elements and inner transition elements.

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