Families of the Periodic Table The elements of the periodic table can be classified into three main groups: metals, semimetals or metalloids, and nonmetals. In addition, certain columns of the periodic table have recognizable features. Metalloid Metal Nonmetal

A dividing line exists in the periodic table beginning between boron and aluminum and proceeding stepwise down to the right (i.e., passing next between aluminum and silicon and then between silicon and germanium).

Metals are those elements found to the left of this line, nonmetals are on the right of this line, with the semimetals or metalloids lying along the line.

More About the Families Alkaline Earth Metals Alkali Metals Halogens Noble Gases Boron Family Carbon Family Nitrogen Family Oxygen Family Transition metals Lanthanides Actinides

Main Group Elements All groups (vertical columns found in the periodic table) are called families. All elements in each group (or family) share many physical and chemical properties. One trend in the periodic table is that elements of the same family share properties Include: Alkali Metals (Group 1) Alkaline Earth Metals (Group 2) Boron Family (Group 3 or 13) Carbon Family (Group 4 or 14) Nitrogen Family (Group 5 or 15) Oxygen Family (Group 6 or 16) Halogens (Group 7 or 17) Noble Gases Group 8 or 18)

Alkali Metals Alkali metals include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr). Physical Properties of Alkali Metals: soft silvery-white good conductor of heat good conductor of electricity 1 valence electron

Reactions and uses of alkali metals: Form a +1 ion, because they give up their one valence electron. Form salts with elements from the halogen family (eg. NaCl is table salt). React spontaneously with oxygen or moisture. Produce a lot of heat when reacting. So much so, they effectively explode. Sodium is used in making paper, making soap, in oven cleaners. Sodium and potassium are important in transmitting nerve impulses in your body.

Alkaline Earth Metals Alkaline earth metals include beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). Physical properties of alkaline earth metals: fairly soft and light-weight silvery-grey good conductors of heat good conductors of electricity 2 valence electrons

Reactions and uses of alkaline earth metals: Used in airplane jet engines. Resists corrosion, so they are good for cars and bikes. Burns fast and brightly in oxygen. Essential for your heart, and for muscle contraction. Used in fireworks to give color.

Boron Family The boron family includes boron (B), aluminum (Al), gallium (Ga), indium (In), and thallium (Tl). Physical properties of the boron family include: Silver Good conductors of heat Good conductors of electricity Boron is a metalloid, the others are metals. Very abundant in the Earth’s crust Low density, light weight Have 3 valence electrons

Reactions and uses of the boron family: Aluminum is everywhere in your life…foil, cans, your bike, cars, etc. Resists rusting (corrosion). Used in long electric cables to conduct electricity over great distances. Gallium will melt in your hand.

Carbon Family The carbon family includes carbon (C), silicon (Si), germanium (Ge), tin (Sn), and lead (Pb). Carbon is a nonmetal, silicon and germanium are metalloids, and tin and lead are metals. Physical properties of the carbon family include: Have 4 valence electrons Can react with almost anything Will share, rather than lose or gain electrons Very abundant on Earth Tend to be dark in color Silicon

Reactions and uses of the carbon family: Silicon is found in sand and is used to make glass, computer chips, breast implants, and sealants. Silicon glass does not break when heated (this is what Pyrex glass is made from in the lab). Tin is used as a protective coating for steel to prevent rust. Lead is used in batteries. Lead is poisonous, particularly to growing children and teens. It causes brain damage. It is often found in paint and water.

Nitrogen Family The nitrogen family includes nitrogen (N), phosphorous (P), arsenic (As), antimony (Sb), and bismuth (Bi). Nitrogen and phosphorous are nonmetals, arsenic and antimony are metalloids, and bismuth is a metal. Physical properties of the nitrogen family include: Have 5 valence electrons Useful in proteins and DNA Only bismuth is a good conductor of electricity Nitrogen is a gas, the others are solid

Reactions and uses for the nitrogen family: Nitrogen makes up 79% of the Earth’s atmosphere. Nitrogen is necessary for life. Red phosphorus is used to make matches. Gallium Arsenide is a good semiconductor used in computers. Ammonia (containing nitrogen) is used in everything from fertilizers to household cleaners. It is secreted in your urine.

Oxygen Family The oxygen family includes oxygen (O), sulfur (S), selenium (Se), tellurium (Te), and polonium (Po). Polonium is a metalloid, all the others are nonmetals. Properties of the oxygen family include: Have 6 valence electrons Oxygen is a gas, the others are all solid Abundant on the Earth Variety of colors

Reactions and uses of the oxygen family: Reacts with metals and nonmetals covalently. Some compounds can be unstable, like ozone. Oxygen is in hydrogen peroxide, used as a cleaner. You cannot live without breathing oxygen. Sulfuric acid is very important as a strong acid in batteries, fertilizers, and detergents. Selenium reacts to light and changes shape.

Halogens Halogens include fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). Physical properties of halogens include: nonmetal Don’t exist free in nature. They are always bound. Form salts with alkali metals. Have 7 valence electrons. Chlorine, fluorine, and bromine are gases.

Reactions and uses of the halogens: Used in everything from household cleaners to table salt. Fluoride prevents tooth decay. Chlorine and bromine kill bacteria and is used in pools and drinking water. Iodine works as an antibiotic. All are poisonous to humans in their natural form. Silver bromide is used on film.

Noble Gases Noble gases include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Ra). Physical properties of the noble gasses include: All nonmetal All gasses Nonreactive 8 valence electrons Produce light when heated

Reactions and uses of noble gasses: Helium is lighter than air and rises, so it is used in balloons. Neon and several other noble gasses glow different colors when electricity is passed through them, so they are used inlights. Noble gasses do not burn.

Transition Metals Include: Central Transition Metals Inner Transition Metals Including: Lanthanides Actinides

Transition Elements Transition metals include too many elements to name here. Look at your periodic table. Transition elements are ALL metals. As you can see here, they have very different appearances.

Reactions and uses of transition metals: The properties of each transition metal is unique, coming from its atomic structure. Many transition metals can be mixed together to form even stronger metals, called alloys. Some can be corroded in air (rust), while others do not. Most have very high melting points.

Reactions and uses of transition metals: Mercury is the only liquid metal. If it is absorbed into the body, it causes a person to go crazy. For many years, mercury was found in thermometers. Iron is the strongest metal we have and is often used as a building material. Transition metals are used in coins. Rare transition metals, like gold and silver, are worth a lot of money.

Lanthanides are very strong and are often included in alloys to help make other metals stronger. They are also used in the glass industry, in welding goggles and face masks, because they absorb radiation that can damage eyes. Lanthanides Lanthanides used to be called rare earth elements because it was thought that they were rare and were only found on Earth. We now know this is not true.

Actinides Actinides are typically radioactive, meaning they give off particles (protons and neutrons) that can damage your body. Many actinides are used in cancer therapy because the radiation kills the fast-growing cancer cells.