2Noticed that trends repeat every 8th element John NewlandsFirst periodic tableNoticed that trends repeat every 8th elementDeveloped the 14 known elements of the time by massesDeveloped the Law of Octaves (repeat every 8)Ex: Valence ElectronsHe did this in 1864Only 14 elements were known at the time
3Meyer and MendeleevLothar Meyer (German) and Dmitri Mendeleev (Russian)Created the modern periodic table around the same time but they did not work togetherMendeleev is given more credit because he published his work firstMendeleev left blank spacesUndiscovered elementsPredicted the properties of these elementsThey did this in 1869Mendeleev’s predictions were almost perfect as far as atomic properties, appearance, and reactionsEx: Germanium, Scandium, Gallium
4Henry Moseley Rearranged the periodic table No longer by masses Now by atomic numbersPeriodic LawPeriodic repetition of chemical and physical properties of the elements when they are arranged by increasing atomic numberIn 1913 noticed that atomic masses were not the most accurate way to set up the periodic table.Some elements were not in the proper placeSo he rearranged the table by atomic number, which completed all of the periodic patterns
5Metals, Non-Metals, and metalloids Most are malleable and ductileGenerally shinyMost are solid at room temperatureGood conductors of heat and electricityNon-metalsTypically gases or brittle/dull looking solidsPoor conductors of heat and electricityMost abundant element in the human body is a nonmetalMetalloidsProperties of both metals and nonmetalsMetals:Malleable=sheetsDuctile=wireShiny when clean and smoothNonmetal: most abundant in human body is oxygen
6Elements of the same row, fill in their electrons on the same shell Rows (left to right)Also known as PERIODSElements of the same row, fill in their electrons on the same shellHave similar properties:Atomic radius sizeIonization energyelectronegativityShell=energy level
7Columns (top to bottom) Known as FAMILIES/GROUPSHave very similar propertiesSame number of valence electronsSimilarities are more significant than those of periodsReactivenessBondingPhysical properties (malleable/ductile/luster)*Similarities in FamiliesSimilarities are more significant than periods except for those of the lanthanide and actinide seriesAll the elements in the halogen family are very reactive with waterThe more the elements want to create bonds (due to number of valence electrons) the more reactive they tend to be
8Family/Group 1: Alkali Metals Very reactive (1 valence electron)ShinyLight weightSoft metalsMalleable/bendableLow melting pointsReact violently in waterEasily form saltsNever found in the pure form in natureUses: greases, batteries, salts, gasoline, fertilizers, and photographySoft metals- so soft can sometimes be cut with a dull knifeWould not use for coins, houses, etc
9Family/Group 2: Alkaline Earth Metals Highly reactive metalsAll have 2 valence electronsHigh melting pointsHigh densitiesTarnish in airNever found in thepure form in natureGood conductorsUses:Fireworks, alloys, nuclear reactors, cancer treatment, etc.
10Transition Metals Middle section of the periodic table Hard, strong, and shinyHigh melting pointsHigh densitiesGood conductorsNever found in thepure form in natureUses:Alloys, pipes, jewelry, cars, catalystThe elements are in the D sub-block – these transition in out of charges (transition metals)They have their own chemistry – known as inorganic chemistry
11Inner Transition Metals Lower two rowsLanthanide SeriesRare Earth metalsSoft, silvery metalReactivePoor conductorsUses:Flint, glass, nuclear reactors, television screens, etc.Actinide SeriesAll radioactiveSilvery metals4 are natural/rest are man madeNuclear power, pigment in glass, smoke detectors, atomic bombs (plutonium), metal detectors (americium) etcLanthanide series is especially reactive with oxygen
12BCNO Families Four separate but very similar families Have 3-6 valence electronsMetals, nonmetals, and metalloidsMost are solids at room temp.Selectively reactiveUses:Essential to life, electronics, insulators, poisons, fertilizers, etc.
13Group/Family 7: Halogens Highly reactive non-metalsAll have 7 valence electronsPoisonousAll states of matterNever found in the pure formPoor conductorsSelectively ReactiveVery RareUses:Toothpaste, cleaner, photography, insecticides,Reactivity decreases as it moves down the column (Fluorine is the most reactive)As atomic number increases rarity also increases, and become less useful.
14Family/Group 8: Noble Gases Nonreactive non-metals8 valence electronsGaseous stateColorlessTastelessOdorlessUses:Balloons, lights, cancer treatment, headlights (xenon), light bulbs (argon), etc.