Metals, Nonmetals, and Semimetals
Most of the periodic table is composed of metals that are on the bottom left corner of the periodic table and the top right part of the periodic table is the nonmetals and the semimetals are on the middle of the them. semimetals hve properties of metals and some properties of nonmetals, thats the reason why the semimetals are in the midle. Metals Common characteristics: Metallic luster, Generally solids at room temperature, Malleable, Ductile, Conduct heat and electricity, Combine with other metals to form alloys, Form positive ions. Nonmetals Common characteristics: Rarely have metallic luster (shine), usually gases at room temperature, Neither malleable or ductile, Poor conductors of heat and electricity, ussually are as molecules, they Combine with other nonmetals to form covalent bonds, normally form negative ions. Semimetals (Metalloids) are a class of 8 elements that have properties of both metals and nonmetals. Common characteristics are: look metallic but are brittle, neither good conductors or insulators. <ref> atomic structues: metals, nonmetals, semimetals. -retreave date 2-5-09 </ref>
Major categories of Elements
Important Groups/Families of Elements
Groups are the columns of the periodic table. Elements in the same group have similar chemical properties and the same number of valence electrons. The periodic table of elements has diffent groups that have a special name like the Alkali metals (group 1), Alkaline Earth metals (group 2), the Transition metals (all the elements from group 3 to group 12), Halogens (group 17 Known as 7a),and The Noble Gases (group 18 known as 8a).