The Periodic Table is a list of all the known elements. It is organized by increasing atomic number. Remember The atomic number tells you how many PROTONS are in one atom of that element. There are three main groups on the Periodic Table: metals, nonmetals, and metalloids. The left side of the table contains elements with the greatest metallic properties. As you move from left to the right, the elements become less metallic with the far right of the table consisting of nonmetals. The elements in the middle of the table are called transition elements because they are changed from metallic properties to nonmetallic properties. A small group whose members touch the zigzag line are called metalloids because they have both metallic and non metallic properties. Metals are located on the left side and the middle of the periodic table. Metals are shiny solids at room temperature (except for Mercury) with high melting points and densities. Metals are malleable and ductile, meaning they can be hammered into sheets or pulled into wires. Metals are also good conductors. The nonmetals are located on the upper right side of the periodic table. Nonmetals are generally poor conductors of heat and electricity. They are often brittle and have no luster, which means they are not shiny. They have the ability to gain electrons easily because of their location on the periodic table. The metalloids are located on the stair case, or the line between the metals and the nonmetals. The metalloids are: boron, silicon, germanium, arsenic, antimony, and tellurium. Polonium is sometimes considered a metalloid as well. Metalloids have characteristics of metals and nonmetals. They make good semiconductors. The table is arranged in vertical columns called groups or families and horizontal rows called periods Each arrangement is significant. The elements in each vertical column or group have similar properties. Group 1 elements all have 1 valence electron, meaning they have 1 electron in their outer energy level. This gives them similar properties. Group 2 elements all have 2 valence electrons. This also gives them similar properties. Group 6 elements have 6 valence electrons, which also gives them similar properties. Not all of the groups, however, hold true for this pattern. The period or row number tells how many energy levels the atom of that element has. The elements in the first period or row all have one energy level. The elements in period 2 all have 2 energy levels. The elements in period 3 have 3 energy levels and so on. There are a number of major groups with similar properties. They are as follows: This element does not match the properties of any other group so it stands alone. It is placed above group 1 but it is not part of that group. It is a very reactive, colorless, odorless gas at room temperature. 1 outermost energy level electron = 1 valence electron These metals are extremely reactive and are never found in nature in their pure form. They are silver colored and shiny. Their density is extremely low so that they are soft enough to be cut with a knife. 1 outermost energy level electron = 1 valance electron Slightly less reactive than alkali metals. They are silver colored and more dense than alkali metals. 2 valence electrons These metals have a moderate range of reactivity and a wide range of properties. In general, they are shiny and good conductors of heat and electricity. They also have higher densities and melting points than groups 1 & 2. 1 or 2 valence electrons All nonmetals. Very reactive. Poor conductors of heat and electricity. Tend to form salts with metals. (Think NaCl!) 7 valence electrons Non-reactive nonmetals. All are colorless, odorless gases at room temperature. All found in Earths atmosphere in small amounts. 8 valence electrons 1) Where are metals located on the periodic table? 2) Sodium is in period 3how many energy levels does sodium have? 3) Chlorine is in group 7how many valence electrons does chlorine have? 4) What do you call the elements that have characteristics of both metals and nonmetals? 5) Where are the metalloids located?