5.3 Representative Groups Key Concepts Why do the elements in a group have similar properties? What are some properties of the A groups in the periodic table?

Why is hydrogen located on the left side of the periodic table, even though it is a gas? Hydrogen’s location is related to its ________________ configuration and not its properties. electron

Hydrogen is located in group 1 because it has one _______________ electron…it can be used as a fuel in automobiles because it is _________________. valence flammable A valence electron is an electron that is in the __________ or ______________ occupied energy level of an atom. highest outermost

The periodic table has ______ total groups that can be separated into group _____ elements and group ______ elements 18 A B

The periodic table was actually designed to tell you how many valence electrons any of the Group ____ elements have…also called ___________________ groups A representative

The columns in the middle of the periodic table are called Group ____ and often have a variety of ______________, so they don’t follow the valence electron rules B configurations

Put electrons into the energy levels for lithium (Li) and sodium (Na). Valence Electrons Put electrons into the energy levels for lithium (Li) and sodium (Na). Li Na

The elements in Group 1A are called _____________ _______________. The Alkali Metals The elements in Group 1A are called _____________ _______________. These metals have a ___________ valence electron and are extremely reactive. Because they are so reactive, alkali metals are found in nature only in ________________. alkali metals single compounds The reactivity of alkali metals ___________ as you move down the group increases

The Alkaline Earth Metals The elements in Group 2A are called _______________ ____________ metals. All alkaline earth metals have _____ valence electrons. alkaline earth 2

The Alkaline Earth Metals Magnesium Magnesium plays a key role in photosynthesis…it is found in the compound ___________________, which helps plants to trap light energy for making ____________ A mixture of magnesium and other metals can be as strong as steel, but much _______________. The frames of ________________ and backpacks often contain magnesium. chlorophyll sugar lighter bicycles

The Alkaline Earth Metals Calcium Calcium carbonate—a compound of calcium, carbon, and oxygen—is the main ingredient in ___________, ________________, _______________ and ______________ Calcium also helps to build strong __________ and ________________ chalk limestone coral pearls teeth bones

The Boron Family Group 3A contains… the metalloid __________, boron the well-known metal ___________________ and three less familiar metals: ______________, _______________, and _________________ All these elements have _____ valence electrons. boron aluminum gallium indium thallium 3 Boron is found glassware that resists temperature changes

The Carbon Family Silicate compounds in clay Group 4A contains… a nonmetal ________, two metalloids _________ and ________________ two metals _______ and ____________ Except for water, most of the compounds in your body contain _______________. carbon silicon germanium tin lead ____ valence electrons 4 carbon

The Nitrogen Family Group 5A contains… two nonmetals ____________ and ______________ two metalloids ____________ and _______________ one metal ______________ nitrogen phosphorus arsenic antimony bismuth Nitrogen and phosphorus are some of the main components of ___________________ ____ valence electrons 5 fertilizers

three nonmetals ________ ____________ and ______________ The Oxygen Family Group 6A has… three nonmetals ________ ____________ and ______________ two metalloids _________ and _________________. ____ valence electrons oxygen sulfur selenium tellurium polonium 6 Sulfur deposits – used to make sulfuric acid

Oxygen is the most abundant element in Earth’s ______________. The Oxygen Family Oxygen is the most abundant element in Earth’s ______________. crust Complex forms of life need oxygen to stay __________ because oxygen is used to release the energy stored in __________ (cellular respiration) Ozone, ______, is another form of the element oxygen… absorbs harmful radiation emitted by the ________. alive food O3 sun

The Halogens The elements in Group 7A are called _____________. At room temperature, chlorine is a ________, bromine is a ________________, and iodine is a _______________. halogens gas liquid solid ____ valence electrons 7

Despite their physical differences, the halogens have similar ____________ properties. chemical Halogens react easily with most _______________. This photograph shows chlorine reacting with steel wool. metals

The Noble Gases The elements in Group 8A are called ___________ gases. Helium has _____ valence electrons because it is in the first energy level. Each of the other noble gases has ______ valence electrons. All of them have ________ outer energy levels so they are ___________ noble 2 8 full stable

The “nobles” in history did not interact with the common people often The Noble Gases The noble gases are ____________ and ______________ and extremely ___________. The “nobles” in history did not interact with the common people often colorless odorless unreactive Passing an electric current through noble gases causes them to __________ different colors emit

Why do elements in a group have similar chemical properties? Assessment Questions Why do elements in a group have similar chemical properties? They have the same number of valence electrons. They have the same ratio of protons to neutrons. Their atomic masses are multiples of the least massive element of the group. They have the same number of total electrons.

How many TOTAL groups are on the periodic Assessment Questions How many TOTAL groups are on the periodic table? And how many Group A columns? Total = 18 Group A = 8

3. What are the common names for the following groups? Group 1A Assessment Questions 3. What are the common names for the following groups? Group 1A Group 2A Group 7A Group 8A Alkali metals Alkaline earth metals halogens Noble gases