Organization of the Periodic Table Chapter 7 Lesson 1 Organization of the Periodic Table

How are the elements on the Periodic Table arranged? The elements are arranged on the periodic table according to their atomic number. Each element is on a square, and it contains key information. Highlight This!! Remember? Atomic Number Element Name Element Symbol Mass Number

Periods and Groups The periodic table is also arranged into horizontal rows called Periods. These are numbered 1 to 7 As you go across a period, the atomic number increases by 1. Highlight This!!

Periods and Groups There are also vertical columns on the periodic table called Groups. These are numbered 1 to 18 Generally, groups of elements have similar chemical and physical properties.

What in the world are those elements at the bottom? The elements at the bottom of the periodic table are called the Lanthanide and Actinide Series. These are known as the rare earth elements. Highlight This!! They are metals! Highlight This!! They are on the bottom in order to save space. This is too much empty space!!!

Facts about the rare earth elements Lanthanides are used in products such as hybrid cars, permanent magnets, and more. The actinide americium is used in smoke detectors. Elements that have an atomic number greater than uranium (92) are often called "transuranium." Many of these elements are man-made under the conditions of nuclear reactors. Both actinides and lanthanides are highly reactive with elements from the halogen group.

Facts about the rare earth elements All of the lanthanides have at least one stable isotope except for promethium. None of the actinides have a stable isotope. They are all radioactive. In WWII, atomic bombs were charged with the actinide plutonium. Plutonium was a power source for Voyager space crafts launched in 1977 Plutonium is also used in artificial heart pacemakers.

Facts about the rare earth elements Plutonium was also used to generate the 1.21 gigawatts of electricity needed to power the DeLorean time machine. https://www.youtube.com/watch?v=MVDosiqfJE0

Metals The metal blocks are colored blue in your textbook. Properties of Metals: Luster, which is shine Malleable, which means it can be hammered or pressed without cracking. Ductile, which means they can be stretched or pulled into wires. Conductive, which is the ability to transfer electricity or heat.

Reactive Metals The most reactive metals are found in group 1 and 2. Highlight This!! Reactive means it combines easily with other substances to form compounds. The metals in group 1 and 2 are so reactive that they are never found in nature by themselves! They react with water and the oxygen in the air.

Nonmetals Nonmetal blocks are colored yellow in your textbook. Their properties are opposite of the properties of metals: Brittle, which means they break easily. They do not have luster. They cannot be easily shaped. They are not good conductors of heat and electricity.

Reactive Nonmetals The most reactive nonmetals are located in group 17 of the periodic table. Highlight This!! They are known as halogens Highlight This!! They are also not found by themselves in nature.

Noble Gases The noble gases are nonmetals, but they are unique. They make up group 18 of the periodic table. Highlight This!! The noble gases are extremely stable, so they ARE often found by themselves in nature. If they are found in compounds, it is not a natural compound. Because scientists have figured this out, we now know that the noble gases are not unreactive.

Semimetals or Metalloids Semimetals are colored green in your textbook. They have properties of both metals and nonmetals. They are good semiconductors…which means they don’t conduct electricity as well as a metal, but they do conduct electricity better than a nonmetal.

Importance of Semiconductors The combination of different semiconductor types together helps control electrical signals. Semiconductors are used to manufacture electronic devices and integrated circuits. Like radios, TV's, computers, video games, and medical diagnostic equipment.

Different types of periodic tables Even though we use 1 periodic table in this class, it is important to know that it is not the ONLY kind of periodic table. Different types of scientists needs periodic tables with different information. For example: Chemists and physicists need information about atomic structures and astronomers need information on how much of each element is found in the solar system.