How is the periodic table divided into metals and nonmetals?  

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gsenviro eNotes educator| Certified Educator

The periodic table of elements is an arrangement of chemical elements in rows and columns, according to certain characteristics. The different rows are called periods, while the columns are called groups. The elements are arranged according to the atomic numbers, electronic configurations and chemical characteristics. The elements with fully filled configurations (the noble gases) constitute the last group (on the right side) of the periodic table. As we move across a row, from left to right, one electron is added to every subsequent element. This means that elements on the left side of the periodic table will have a higher tendency to donate electrons, while the ones close to the noble gases will have a higher tendency to accept electrons. Thus, the metals are on the left side of the table, while non-metals are towards the right side of the table. 

Since there are many more metals than non-metals, most of the table is occupied by metals. In fact, metals occupy the left two groups, the entire central section (transition metals) and parts of the groups on the right sides, apart from the two bottom rows (actinides and lanthanides). 

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