Sabado, Pebrero 18, 2012

HOW TO UNDERSTAND THE PERIODIC TABLE






1.Begin by viewing the table. The rows are called periods and are listed in order of their atomic number from lowest to highest. The atomic number represents the number of protons found in the nucleus of their atoms. The columns are called groups. The groups are considered the most important means of identifying the metals. The groupings are called alkali metals, alkali earth metals, halogens, noble gases, transition metals, rare earth metals, other metals and other non-earth metals. The groups indicate similar chemical properties and the same type of electron configurations in their valence shell.
The electrons in the outer shell are called valence electrons, which determine how reactive a metal is to other metals. The Roman numerals above each group of elements specify the usual number of valence electrons. The "a" and "b" included next to the Roman numerals determine where the electrons reside. Representative elements are "a" and their electrons reside in the "s" and "p" sub-levels. The non-representative elements are "b" and their electrons reside in the "d" and "f" sub-levels.

2.
Look at the table and find iron, or Fe. Fe stands for the Latin word ferrum. Fe has a series of numbers around it. To locate iron find it in group 8 VIIIb. Above the abbreviation of Fe is its atomic number, which is 26. Usually below the Fe is the atomic weight, which is 55.847. Some periodic tables vary to some degree in the information and configuration but the atomic number and atomic weight will be present.

3. 
 Notice a separate group of metals at the bottom. This group is called the rare earth metals. Most of the rare earth metals are man made. There are 30 of these metals, and they reside in group 3 in rows 6 and 7. These metals comprise two series of metals called lanthanide and actinide.