The History and The History and Arrangement of Arrangement of

the Periodic Tablethe Periodic Table

History of the Periodic TableHistory of the Periodic Table

►1869 – Dmitri Mendeleev (Russian 1869 – Dmitri Mendeleev (Russian Chemist) thought elements may have Chemist) thought elements may have something in common.something in common.

►Organized the elements into a tableOrganized the elements into a table►Made each element a card and listed Made each element a card and listed

its properties known at the time its properties known at the time (mass, density, color, melting point (mass, density, color, melting point and valence number).and valence number).

Dmitri Mendeleev (cont.)Dmitri Mendeleev (cont.)

►Mendeleev organized each card (element) Mendeleev organized each card (element) according to its according to its atomic mass (mass #)atomic mass (mass #)

►Noticed a repeating pattern of valence Noticed a repeating pattern of valence numbers (1,2,3,4,5 etc..)numbers (1,2,3,4,5 etc..)

►Noticed elements fell in to columns (groups)Noticed elements fell in to columns (groups)►Noticed all elements in a column had the Noticed all elements in a column had the

same valence number and showed similar same valence number and showed similar physical and chemical properties. physical and chemical properties.

Henry MoseleyHenry Moseley

►Mendeleev left blank spaces in his Mendeleev left blank spaces in his table so elements would line up – he table so elements would line up – he also predicted what properties the also predicted what properties the undiscovered elements would have.undiscovered elements would have.

►1913 – Henry Moseley (English 1913 – Henry Moseley (English Scientist) changed the arrangement of Scientist) changed the arrangement of the periodic table. Instead of by the periodic table. Instead of by increasing atomic mass (mass #), it increasing atomic mass (mass #), it was arranged by increasing: was arranged by increasing: atomicatomic number (# of protons)number (# of protons)..

Arrangement of the Periodic Arrangement of the Periodic TableTable

► Systematic arrangement of the Systematic arrangement of the elementselements

►Arranged by Arranged by atomic numberatomic number and and propertiesproperties

►Numbered Numbered groups / familiesgroups / families are in are in vertical columns vertical columns

► PeriodsPeriods are by amount of energy levels are by amount of energy levels in horizontal rows (1-7)in horizontal rows (1-7)

►Divided into Divided into metalsmetals, , nonmetalsnonmetals and and metalloidsmetalloids

Metals - propertiesMetals - properties

► Elements that begin at the left side of Elements that begin at the left side of the periodic table the periodic table

►Good conductors of electricityGood conductors of electricity► ShinyShiny►Ductile – can be drawn into thin wiresDuctile – can be drawn into thin wires►Malleable – can be hammered into thin Malleable – can be hammered into thin

sheets and other shapessheets and other shapes►High melting pointHigh melting point► Tend to loose electronsTend to loose electrons

Nonmetals - propertiesNonmetals - properties

► Elements that are to the right of the Elements that are to the right of the zigzag on the periodic tablezigzag on the periodic table

►Not shiny, dull in appearanceNot shiny, dull in appearance►Do not conduct heat or electricityDo not conduct heat or electricity►Are brittle and break easilyAre brittle and break easily► Cannot be drawn into wire or Cannot be drawn into wire or

hammered into sheetshammered into sheets► Lower densitiesLower densities► Lower melting points Lower melting points ► Tend to gain electronsTend to gain electrons

Metalloids - propertiesMetalloids - properties

►Elements that are found along Elements that are found along both sides of the zigzag line both sides of the zigzag line

►SolidsSolids►Can be shiny or dull conduct heat Can be shiny or dull conduct heat

and electricity better than and electricity better than nonmetals but not as well as nonmetals but not as well as metalsmetals

►Both ductile and malleableBoth ductile and malleable

Chemical Groups Chemical Groups (Families)(Families)

►Elements that are in the same Elements that are in the same group or family (column) of the group or family (column) of the Periodic Table have similar Periodic Table have similar properties because they have the properties because they have the same number of valence electronssame number of valence electrons

►1 valence electron in outer energy 1 valence electron in outer energy level level

►Very reactive substances so it Very reactive substances so it easily bonds with other substanceseasily bonds with other substances

►Easily loses 1 electron to form a Easily loses 1 electron to form a stable +1 ion (ionic bond)stable +1 ion (ionic bond)

►Never found alone in natureNever found alone in nature►Soft, silver-white, shinySoft, silver-white, shiny

Group (Family) 1 - Alkali Group (Family) 1 - Alkali MetalsMetals

Group (Family) 2 - Alkaline Group (Family) 2 - Alkaline Earth Earth MetalsMetals

► 2 valence electrons in outer energy level2 valence electrons in outer energy level► Loses 2 electrons to form +2 ionsLoses 2 electrons to form +2 ions► Second most reactive elements but not Second most reactive elements but not

as reactive as group #1, so bonds easily as reactive as group #1, so bonds easily with other substanceswith other substances

►Never found alone in natureNever found alone in nature►Will always bond ionically in natureWill always bond ionically in nature► Found combined with oxygen and other Found combined with oxygen and other

non-metals in the Earth’ crustnon-metals in the Earth’ crust

Groups 3-12Groups 3-12 The The Transition Transition

MetalsMetals►1 or 2 valence electrons 1 or 2 valence electrons ►Can lose and or share valence Can lose and or share valence

electronselectrons►Can have many multiple electrons in Can have many multiple electrons in

22ndnd to last energy levels to last energy levels►Common metals – gold, silver & Common metals – gold, silver &

coppercopper►The U.S. imports at least 60 of these The U.S. imports at least 60 of these

types of elements which are strategic types of elements which are strategic and vital for our economyand vital for our economy

From Metals to NonmetalsFrom Metals to Nonmetals((outer energy level)outer energy level)

► Group 13 – Boron Group/FamilyGroup 13 – Boron Group/Family 3 valence 3 valence electronselectrons

- metalloids and metals in group- metalloids and metals in group - usually bonds covalently- usually bonds covalently

► Group 14Group 14 Carbon GroupCarbon Group 4 valence 4 valence electronselectrons

- non-metals, metals and metalloids- non-metals, metals and metalloids - will always bond covalently ( electron sharing)- will always bond covalently ( electron sharing) - contain elements which are essential for cell - contain elements which are essential for cell

functionsfunctions

► Group 15Group 15 Nitrogen GroupNitrogen Group 5 valence electrons5 valence electrons - non-metals, metalloids and metals- non-metals, metalloids and metals

- will always bond covalently- will always bond covalently► Group 16Group 16 Oxygen GroupOxygen Group 6 valence 6 valence

electronselectrons

- non-metals, metalloids and metals- non-metals, metalloids and metals - will bond covalently and ionically in nature- will bond covalently and ionically in nature

► Group 17Group 17 Halogen GroupHalogen Group 7 valence electrons7 valence electrons

- all non-metals that are very reactive and form compounds- all non-metals that are very reactive and form compounds called halides ( salts) called halides ( salts) - bonds covalently and ionically- bonds covalently and ionically

► Group 18Group 18 Noble GasesNoble Gases 8 valence 8 valence electronselectrons

- colorless- colorless

- non-reactive ( inert ) / very stable- non-reactive ( inert ) / very stable

- have a full outer shell filled - have a full outer shell filled

with electronswith electrons

- non-metals- non-metals

Rare Earth ElementsRare Earth Elements(Inner Transition Metals)(Inner Transition Metals)

►First Row – Lanthanide Series First Row – Lanthanide Series - naturally found rare Earth metals- naturally found rare Earth metals - all but one is non-radioactive- all but one is non-radioactive

►Second Row – Actinide SeriesSecond Row – Actinide Series - most are man-made and radioactive- most are man-made and radioactive - many are short-lived- many are short-lived