Introduction to the Periodic Table
The Periodic table is an arrangement of elements in the order of their
increasing atomic numbers to show that elements have related properties. Earlier
tables, such as those of Dmitry Mandeleev (photograph) (1869) and
Lother Meyer (1869-70) were based on atomic weights which are measured as
bulk properties and valency relationships. At that time the concept of atomic
numbers was unknown. The main purpose of the periodic table was:
- Classification elements into groups with similar properties.
- To predict the possibilities of new elements based on their
properties.
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The modern form of the periodic law states that properties of the
elements are the periodic function of their atomic numbers and the properties of
the elements depend on their electronic configuration.
The modern periodic table consists of arrangements of elements in three broad
categories.
| - metals (located on LHS) - non-metals (located on
RHS)
- metalloids ( in between) |
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