Props. in a group are similar Props. in a group are similar because the atoms have the same because the atoms have the same # of electrons in their outer # of electrons in their outer energy levelsenergy levelsAtoms will take, give or share Atoms will take, give or share electrons with each other in order electrons with each other in order to have a complete set of to have a complete set of electronselectronsElements that undergo this Elements that undergo this process are called reactiveprocess are called reactive

Contains metalsContains metals 1 electron in the outer level1 electron in the outer level Soft enough to cut with a knifeSoft enough to cut with a knife Silver color, shiny, low densitySilver color, shiny, low density Very reactive, react with water to form hydrogen gasVery reactive, react with water to form hydrogen gas Most reactive metals because they can easily give away Most reactive metals because they can easily give away

the one outer shell electronthe one outer shell electron So reactive that in nature they are found only combined So reactive that in nature they are found only combined

with other elementswith other elements Cmpds. formed from them are very usefulCmpds. formed from them are very useful Ex.-Sodium Cholride-Table salt, Potassium Bromide-Used Ex.-Sodium Cholride-Table salt, Potassium Bromide-Used

in photographyin photography

2 electrons in outer level2 electrons in outer level Very reactive, but less reactive than Very reactive, but less reactive than

alkali metalsalkali metals More difficult for atoms to give 2 More difficult for atoms to give 2

electrons than 1 when joining with electrons than 1 when joining with other atomsother atoms

Other properties: Silver color, higher Other properties: Silver color, higher densities than alkali metalsdensities than alkali metals

1 or 2 electrons in the outer level1 or 2 electrons in the outer level Less reactive than alkaline-earth metalsLess reactive than alkaline-earth metals Other properties: Shininess, good conductors of thermal Other properties: Shininess, good conductors of thermal

energy and electric current, higher densities and MP energy and electric current, higher densities and MP than elements in Groups 1 and 2 (except mercury-liquid than elements in Groups 1 and 2 (except mercury-liquid @ room temp.)@ room temp.)

Many are silver-not all-Gold is an exampleMany are silver-not all-Gold is an example Some are reactive and some are not that reactiveSome are reactive and some are not that reactive Lanthanides & Actinides:placed below the table so the Lanthanides & Actinides:placed below the table so the

table is not so widetable is not so wide Lanthanides:shiny, reactive metals.Lanthanides:shiny, reactive metals. Actinides:radioactive(unstable)Actinides:radioactive(unstable) Elements after 94 are made in labsElements after 94 are made in labs

• This group contains one metalloid and four metals

• 3 electrons in the outer level• They are reactive• They are solid at room temp.• Most common element is Aluminum-

most metal found in the Earth’s crust

Contains 1 nonmetal, 2 metalloids and 2 Contains 1 nonmetal, 2 metalloids and 2 metalsmetals

4 electrons in the outer level4 electrons in the outer level The reactivity varies among the elementsThe reactivity varies among the elements Solid at room temperatureSolid at room temperature Example of a nonmetal in the Carbon group: Example of a nonmetal in the Carbon group:

Diamonds: hardest material known. Soot: Diamonds: hardest material known. Soot: formed from burning oil, coal and wood.formed from burning oil, coal and wood.

Both are natural forms of CarbonBoth are natural forms of Carbon

Contains 2 nonmetals, 2 metalloids and 1 Contains 2 nonmetals, 2 metalloids and 1 metalmetal

5 electrons in the outer level5 electrons in the outer level Reactivity varies among the elementsReactivity varies among the elements Solid at room temp. except for nitrogen (it Solid at room temp. except for nitrogen (it

is a gas) 80% of the air you breatheis a gas) 80% of the air you breathe Nitrogen-not very reactive but Nitrogen-not very reactive but

Phosphorous is extremely reactive (striking Phosphorous is extremely reactive (striking a match)a match)

Contains 3 nonmetals, 1 metalloid, and 1 Contains 3 nonmetals, 1 metalloid, and 1 metalmetal

6 electrons in the outer level6 electrons in the outer level These elements are reactiveThese elements are reactive All but oxygen are solid at room temp.All but oxygen are solid at room temp. Oxygen makes up about 20% of the air Oxygen makes up about 20% of the air

you breathe.you breathe.

Contains nonmetalsContains nonmetals 7 electrons in the outer level7 electrons in the outer level Very reactive because their atoms only Very reactive because their atoms only

need to gain only 1 electron to have a need to gain only 1 electron to have a complete outer levelcomplete outer level

Poor conductors of electric current, violent Poor conductors of electric current, violent reactions with alkali metals to form salts, reactions with alkali metals to form salts, never in uncombined forms in naturenever in uncombined forms in nature

Contains nonmetalsContains nonmetals 8 electrons in the outer level (except 8 electrons in the outer level (except

helium which has 2)helium which has 2) Unreactive elements-full set of electrons in Unreactive elements-full set of electrons in

their outer leveltheir outer level Colorless, odorless gases at room temp.Colorless, odorless gases at room temp. These are useful gases-argon: lightbulbs, These are useful gases-argon: lightbulbs,

helium: makes blimps and weather helium: makes blimps and weather balloons floatballoons float

1 electron in the outer level1 electron in the outer level Hydrogen is reactiveHydrogen is reactive Properties of H do not match any other group so it is set Properties of H do not match any other group so it is set

apart.apart. Colorless, odorless gas at room temp., low density, Colorless, odorless gas at room temp., low density,

explosive reaction with oxygenexplosive reaction with oxygen Can give away one electron when they join with other Can give away one electron when they join with other

atoms.atoms. Physical props. of hydrogen are more like nonmetals than Physical props. of hydrogen are more like nonmetals than

metals.metals. Hydrogen is found in stars. Most abundant element in the Hydrogen is found in stars. Most abundant element in the

universe.universe. Useful in rocket fuel because it is so reactiveUseful in rocket fuel because it is so reactive