Table of Contents Chapter: The Periodic Table Section 1: Introduction to the Periodic Table Section 2: Representative Elements Section 3: Transition Elements
1 Introduction to the Periodic Table Development of the Periodic Table Mendeleev s Table of Elements By 1830, fifty-five different elements had been isolated and named. In 1869, Mendeleev arranged elements in order of increasing atomic mass and found that elements with similar properties fell into groups.
1 Introduction to the Periodic Table Development of the Periodic Table Mendeleev s Table of Elements Moseley improved the periodic table by arranging the elements according to atomic number instead of atomic mass.
1 Introduction to the Periodic Table Today s Periodic Table The modern periodic table contains 7 periods, or rows, of elements whose properties change gradually and 18 groups, or columns, each with a family of elements having similar properties.
1 Introduction to the Periodic Table Today s Periodic Table
1 Introduction to the Periodic Table Zones on the Periodic Table Groups 1 and 2 along with groups 13 to 18 are called the representative elements.
1 Introduction to the Periodic Table Zones on the Periodic Table Groups 3 to 12 are called the transition elements (all metals).
1 Introduction to the Periodic Table Zones on the Periodic Table Some transition elements, called the inner transition elements, are placed below the main table. These elements are called the lanthanide and actinide series because one series follows the element lanthanum, element 57, and the other series follows actinium, element 89.
1 Metals If you look at the periodic table, you will notice it is color coded. The colors represent elements that are metals, nonmetals, or metalloids. Introduction to the Periodic Table
1 Introduction to the Periodic Table Metals A metal has luster, conducts heat and electricity, and is malleable and ductile. Luster reflects light Malleable hammered into sheets Ductile pulled into wires
1 Introduction to the Periodic Table Nonmetals and Metalloids Nonmetals are usually gases or brittle solids at room temperature and poor conductors of heat and electricity.
1 Introduction to the Periodic Table Nonmetals and Metalloids There are only 17 nonmetals, but they include many elements that are essential for life carbon, sulfur, nitrogen, oxygen, phosphorus, and iodine.
1 Introduction to the Periodic Table Nonmetals and Metalloids A metalloid shares properties with metals and nonmetals.
1 Introduction to the Periodic Table The Element Keys
1 Introduction to the Periodic Table The Element Keys Symbols are abbreviations often based on the element s name
1 Introduction to the Periodic Table Symbols for the Elements
1 Question 1 Section Check Horizontal rows in the periodic table are known as. A. lines B. periods C. tables D. walls
Section Check 1 Answer The answer is B. Atomic number increases across a period.
1 Question 2 Section Check In 1869, this famous scientist invented the first version of the periodic table of elements, though there have been many changes since his day.
1 Answer Section Check The scientist was Dmitri Mendeleev. Though his name may not be as familiar to you as Isaac Newton or Albert Einstein, Mendeleev is arguably as important a figure in the history of science.
1 Question 3 Section Check What is the particular name given to groups 3 through 12 on the periodic table? Answer These groups are known as the transition elements. On either side of them are the representative elements.
2 Representative Elements Groups 1 and 2 Groups 1 and 2 are active metals found in nature combined with other elements; although hydrogen is placed in Group 1, it is not a metal and shares properties with Groups 1 and 17.
2 Representative Elements Alkali Metals Alkali Metals (group 1) silvery solids with low densities and low melting points; they increase in reactivity from top to bottom of the periodic table.
2 Representative Elements Alkaline Earth Metals Alkaline-earth metals (Group 2) are denser, harder, have higher melting points, and are slightly less reactive than alkali metals in the same period.
2 Representative Elements Groups 13 through 18 Groups 13 through 18 may contain metals, nonmetals, or metalloids in solid, liquid, or gas form.
2 Representative Elements Group 13 The Boron Family The boron family elements in group 13 are all metals except boron, which is a metalloid; these elements are used in a variety of products. Cookware made with boron can be moved directly from the refrigerator into the oven without cracking.
2 Representative Elements Group 13 The Boron Family Aluminum is used to make soft-drink cans, cookware, siding for homes, and baseball bats. Gallium is a solid metal, but its melting point is so low that it will melt in your hand. It is used to make computer chips.
2 Representative Elements Group 14 The Carbon Group The carbon group elements are all metalloids or metals, except for carbon itself.
2 Representative Elements Group 14 The Carbon Group Carbon is found in all living things and exists in several forms Graphite Diamond Coal Bucky balls
2 Representative Elements Group 14 The Carbon Group Silicon and germanium are used in electronics as semiconductors
2 Representative Elements Group 14 The Carbon Group Tin and lead are the two heaviest elements in Group 14. Lead is used to protect your torso during dental X rays. It also is used in car batteries, low-milting alloys, protective shielding around nuclear reactors, and containers used for storing and transporting radioactive materials. Tin is used in pewter, toothpaste, and the coating on steel cans used for food.
2 Representative Elements Group 15 The Nitrogen Group The nitrogen group contains nitrogen and phosphorus, which are required by living things and which are used in industry. About 80% of our air is nitrogen.
2 Representative Elements Group 15 The Nitrogen Group The element phosphorus comes in two forms white and red. White phosphorus is so active it can t be exposed to oxygen in the air or it will burst into flames. The heads of matches contain the less active red phosphorus, which ignites from the heat produced by friction when the match is struck.
2 Representative Elements Group 15 The Nitrogen Group Phosphorous compounds are essential ingredients for healthy teeth and bones. Plants also need phosphorus, so it is one of the nutrients in most fertilizers.
2 Representative Elements Group 16 The Oxygen Family The oxygen family contains oxygen and sulfur, which are essential for life and used to manufacture many products.
2 Representative Elements Group 16 The Oxygen Family Ozone, a less common form of oxygen, is formed in the upper atmosphere through the action of electricity during thunderstorms. The presence of ozone is important because it shields living organisms from some harmful radiation from the Sun.
2 Representative Elements Group 16 The Oxygen Family Selenium conducts electricity when exposed to light, so it is used in solar cells, light meters, and photographic materials.
2 Representative Elements Group 17 The Halogen Group The halogen group elements form salts with sodium and with the other alkali metals. Halogen means salt former
2 Representative Elements Group 18 The Noble Gases The noble gases rarely combine with other elements, they are often used in lighting and inflating balloons.
2 Representative Elements Uses for the Noble Gases The neon lights you see in advertising signs can contain any of the noble gases, not just neon. Electricity is passed through the glass tubes that make up the sign. Helium glows yellow, neon glows red-orange, and argon produces a bluish-violet color.
2 Representative Elements Uses for the Noble Gases Argon, the most abundant of the noble gases on Earth, was first found in 1894. Krypton is used with nitrogen in ordinary lightbulbs because these gases keep the glowing filament from burning out. Krypton lights are used to illuminate landing strips at airports, and xenon is used in strobe lights and was once used in photographic flash cubes.
2 Representative Elements Uses for the Noble Gases At the bottom of the group is radon, a radioactive gas produced naturally as uranium decays in rocks and soil. If radon seeps into a home, the gas can be harmful because it continues to emit radiation. When people breathe the gas over a period of time, it can cause lung cancer.
2 Question 1 Section Check What does the term halogen mean?
2 Answer Section Check Halogen means saltformer. All the halogens form salts with sodium (and other alkali metals).
2 Question 2 Section Check Why is it important to have a layer of ozone in our upper atmosphere? Answer Ozone shields us from dangerous forms of radiation that come from the Sun.
2 Question 3 Section Check Almost 80% of the air you are breathe consists of. A. oxygen B. nitrogen C. halothane D. argon
2 Answer Section Check The answer is B. Most people think they are just breathing oxygen, but in fact they are mostly breathing in nitrogen!
3 Transition Elements The Metals in the Middle Groups 3 to 12 are the transition elements; most are combined with other elements in ores.
3 Transition Elements The Iron Triad The iron triad is composed of iron, cobalt, and nickel; these metals have magnetic properties.
3 Transition Elements The Iron Triad Industrial magnets are made from an alloy of nickel, cobalt, and aluminum. Nickel is used in batteries along with cadmium. Iron is a necessary part of hemoglobin, the substance that transports oxygen in the blood. Iron also is mixed with other metals and with carbon to create a variety of steels with different properties.
Platinum group Ruthenium, rhodium, palladium, osmium, indium, and platinum are part of the platinum group.
3 Transition Elements Uses of Transition Elements Tungsten has the highest melting point of any metal (3,410 C) and will not melt when a current passes through it. The filaments of lightbulbs are made of tungsten, element 74.
3 Transition Elements Uses of Transition Elements Mercury, which has the lowest melting point of any metal ( 39 C), is used in thermometers and in barometers. Mercury is the only metal that is a liquid at room temperatures. Like many of the heavy metals, mercury is poisonous to living beings.
3 Uses of Transition Elements Chromium s name comes from the Greek word for color, chrome. Many other transition elements combine to form substances with brilliant colors. Transition Elements
3 Transition Elements Uses of Transition Elements Several transition elements can be used as catalysts, which are substances that make reactions occur faster without changing itself.
3 Transition Elements Inner Transition Elements The inner transition elements are called lanthanides and actinides. The first series, from cerium to lutetium, is called the lanthanides. The second series of elements, from thorium to lawrencium, is called the actinides.
3 Transition Elements The Lanthanides The lanthanides are soft metals and were once thought to be rare.
3 The Actinides Transition Elements All the actinides are radioactive; several are synthetic elements that do not occur naturally. Uranium is found in Earth s crust because its half-life is long 4.5 billion years.
3 The Actinides Transition Elements Plutonium is used as a fuel in nuclear power plants. Americium is used in some home smoke detectors. Californium-252 is used to kill cancer cells.
3 Transition Elements Dentistry and Dental Materials Dentists have been using amalgam for over 150 years to fill cavities in decayed teeth. Amalgam, a mixture of silver, copper, tin, and mercury, is the familiar silver filling.
3 Transition Elements Dentistry and Dental Materials Because amalgam contains mercury, some people are concerned that the use of this particular type of filling may unnecessarily expose a person to mercury vapor.
3 Transition Elements Dentistry and Dental Materials Dental materials are sometimes made of new composites, resins, and porcelins.
3 Question 1 Section Check Which three elements are known as the iron triad? Answer The iron triad consists of iron, cobalt, and nickel. They are called this because of their similar properties.
3 Question 2 Section Check Which group consists of ruthenium, rhodium, palladium, osmium, iridium, and platinum? Answer The answer is the platinum group. These elements all have similar properties, which is why they are grouped together.
3 Question 3 Section Check What is most notable about the nuclei of the actinides? Answer The nuclei of actinides are unstable. All the actinides are radioactive, which means they decay to form other elements.