periodic table hstry

8/7/2019 periodic table hstry

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The BasicsThe Basics

What does periodic mean?What does periodic mean?

Having or marked by repeated cyclesHaving or marked by repeated cycles

What things in our everyday life do we noticeWhat things in our everyday life do we noticeas cyclic or periodic?as cyclic or periodic?

What are some of the patterns you noticeWhat are some of the patterns you noticeon the periodic table?on the periodic table?

There are many important people whoThere are many important people whoplayed a key role in organizing theplayed a key role in organizing theelements in such an intricate fashionelements in such an intricate fashion


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Antoine Lavoisier (1790s)Antoine Lavoisier (1790s)

Compiled a list ofCompiled a list of

known elements atknown elements at

the time (23)the time (23)

What elements do youWhat elements do youthink were includedthink were included

here?here?

Gold, silver, oxygen,Gold, silver, oxygen,

carboncarbon

The 1800s broughtThe 1800s brought

about big changesabout big changes


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What are some big things that may haveWhat are some big things that may have

affected the knowledge of chemistry?affected the knowledge of chemistry? ElectricityElectricity

Development of the spectrometerDevelopment of the spectrometer

Industrial revolution (midIndustrial revolution (mid--1800s)1800s) Lead to many chemical industriessoaps, dyes,Lead to many chemical industriessoaps, dyes,

fertilizersfertilizers

But not all good things came from the revolutionBut not all good things came from the revolution Chemical pollution now an issueChemical pollution now an issue

70 known elements by the 187070 known elements by the 1870


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In addition to new elementsIn addition to new elements

New scientific data that provided insight into theNew scientific data that provided insight into theproperties of compounds and elementsproperties of compounds and elements

A tool for organization became necessaryA tool for organization became necessary

Big step: 1860Big step: 1860 Scientists agreed on a method for accuratelyScientists agreed on a method for accurately

determining the atomic masses of the elementsdetermining the atomic masses of the elements(finally!)(finally!)

What would be the problem with not having aWhat would be the problem with not having auniversal way to measure the mass of elements?universal way to measure the mass of elements?

Now the search for relationships between massNow the search for relationships between massand elements was onand elements was on


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John Newlands (1864)John Newlands (1864)

English chemistEnglish chemist

Proposed organization schemeProposed organization scheme

Noticed elements were arranged byNoticed elements were arranged byincreasing atomic massincreasing atomic mass

Also, their properties repeated everyAlso, their properties repeated everyeigth elementeigth element 11stst and 8and 8thth

22ndnd and 9and 9thth

What do were call this repeatingWhat do were call this repeatingpattern?pattern?

Newlands called it: The Law ofNewlands called it: The Law of

OctavesOctaves Octave is a group of musical notesOctave is a group of musical notes

that repeats every eighth tonethat repeats every eighth tone


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Newlands organized the first 14 known elementsNewlands organized the first 14 known elements

Elements with similar properties were in the same rowElements with similar properties were in the same row

How does this compare with our current periodic tableHow does this compare with our current periodic table


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The Law of octaves was not readilyThe Law of octaves was not readily

accepted b/c it did not work with allaccepted b/c it did not work with allelementselements

Newlands law was also criticized b/c theNewlands law was also criticized b/c the

use of the word octave was considereduse of the word octave was consideredvery unscientificvery unscientific

The important thing was that NewlandThe important thing was that Newland

recognized that properties of elementsrecognized that properties of elements

were repeatedwere repeated


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Lothar Meyer (1869)Lothar Meyer (1869)

German chemistGerman chemist

DemonstratedDemonstratedconnection betweenconnection between

atomic mass andatomic mass andelemental propertieselemental properties

Did not receive asDid not receive asmuch credit as Dmitrimuch credit as Dmitri

Mendeleev becauseMendeleev becausehe did not publish hishe did not publish hisorganization schemeorganization schemefirstfirst


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Dmitri Mendeleev (1869)Dmitri Mendeleev (1869) Russian chemistRussian chemist

demonstrated connectiondemonstrated connectionbetween atomic mass andbetween atomic mass andelemental propertieselemental properties

Noticed (like Newlands) thatNoticed (like Newlands) thatwhen elements were put inwhen elements were put inorder of atomic mass thereorder of atomic mass therewas a periodic repetition ofwas a periodic repetition oftheir elemental propertiestheir elemental properties

Arranged elements in order

Arranged elements in orderof increasing atomic massof increasing atomic mass

into columns with similarinto columns with similarpropertiesproperties

This was the first periodicThis was the first periodic

tabletable


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Mendeleevs table was widely acceptedMendeleevs table was widely acceptedbecause it predicted the existence andbecause it predicted the existence and

properties of undiscovered elementsproperties of undiscovered elements

Blank spaces on the tableBlank spaces on the table Predicted properties of yet to bePredicted properties of yet to be

discovered elements such as scandium,discovered elements such as scandium,

gallium, and germaniumgallium, and germanium


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But there were problemsBut there were problems

New elements discovered and atomicNew elements discovered and atomic

masses were more accurately determinedmasses were more accurately determined

Elements in Mendeleevs table not inElements in Mendeleevs table not incorrect ordercorrect order

Arranging elements by mass now putArranging elements by mass now put

groups of elements together with differentgroups of elements together with different

propertiesproperties


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Henry Moseley (1913)Henry Moseley (1913)

English ChemistEnglish Chemist

Figured out the problemFigured out the problemwith Medeleevs Tablewith Medeleevs Table

What did MoseleyWhat did MoseleyDiscover before?Discover before? Atoms of each elementAtoms of each element

contain unique number ofcontain unique number ofprotons in their nucleiprotons in their nuclei

He arranged elements inHe arranged elements in

order of increasingorder of increasing atomicatomicnumbernumber and notand notincreasing atomic massincreasing atomic mass


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Problem Solved!Problem Solved!

Moseleys arrangement solved theMoseleys arrangement solved theproblems with Mendeleevs tableproblems with Mendeleevs table

His arrangement resulted in clear periodicHis arrangement resulted in clear periodicpatterns of propertiespatterns of properties

Lead toLead to Periodic Law:Periodic Law:

Statement that there is a periodic repetition ofStatement that there is a periodic repetition of

chemical and physical properties of thechemical and physical properties of theelements when they are arranged inelements when they are arranged inincreasing atomic numberincreasing atomic number


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Modern Periodic TableModern Periodic Table


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Whats in the box?Whats in the box?

What does the 1 standWhat does the 1 standfor?for? Atomic NumberAtomic Number

This tells us what about anThis tells us what about an

atom of H?atom of H? # of protons# of protons

What does the 1.007947What does the 1.007947stand for?stand for? Atomic MassAtomic Mass

This tells us what about anThis tells us what about anatom of H?atom of H?

Mass in nucleus (# ofMass in nucleus (# ofprotons and neutrons)protons and neutrons)


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On the modern periodic table, how areOn the modern periodic table, how are

elements arranged?elements arranged?

In order of increasing atomic number, left toIn order of increasing atomic number, left to

rightright

What do we call the columns (up andWhat do we call the columns (up and

down) on the periodic table?down) on the periodic table? GROUPS (or families)GROUPS (or families)

What do we call the rows (left and right) onWhat do we call the rows (left and right) on

the periodic table?the periodic table? PERIODSPERIODS


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What does periodic mean?What does periodic mean?

Having or being marked by repeated cyclesHaving or being marked by repeated cycles

What element does period 1 begin with?What element does period 1 begin with? HH

How many periods are there on the table?How many periods are there on the table?

77

PeriodsPeriods


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GroupsGroups Two different number systems for groupsTwo different number systems for groups In the first numbering system, groups areIn the first numbering system, groups are

number 1number 1--8 and each number is followed by8 and each number is followed byeither an A or Beither an A or B

The groups labeled A are the main groups (1AThe groups labeled A are the main groups (1Athru 8A)thru 8A) Representative elementsRepresentative elements

This is because they possess a wide range of chemical andThis is because they possess a wide range of chemical andphysical propertiesphysical properties

The groups designated with a B (1B thru 8B) areThe groups designated with a B (1B thru 8B) arefound in the centerfound in the center Transition ElementsTransition Elements

A more recent numbering system has beenA more recent numbering system has beendevised numbering 1devised numbering 1--1818


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Classification of ElementsClassification of Elements

What was another pattern of organizationWhat was another pattern of organization

you noticed on the periodic table?you noticed on the periodic table?

Physical properties and statesPhysical properties and states

3 main classifications of elements3 main classifications of elements

MetalsMetals

NonmetalsNonmetals

MetalloidsMetalloids


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1. Metals1. Metals

Elements that are shiny,Elements that are shiny,

smooth and cleansmooth and clean

Solid at room temperatureSolid at room temperature

Good conductors of heatGood conductors of heat

and electricityand electricity

MalleableMalleable

Hammered flat into a sheetHammered flat into a sheet DuctileDuctile

Drawn out into a wireDrawn out into a wire


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1. Metals1. Metals

All group B and most group A elementsAll group B and most group A elements

Staircase line is divider between metalsStaircase line is divider between metals

and nonmetals (Boron 3A

andA

statineand nonmetals (Boron 3A

andA

statine7A)7A)

ALMOST all elements on left side of tableALMOST all elements on left side of table

are metalsare metals

What is the exception?What is the exception?

HydrogenHydrogen


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Alkali and Alkaline Earth metalsAlkali and Alkaline Earth metals

(Group A)(Group A) What does alkali mean?What does alkali mean?

basicbasic

Alkali metalsAlkali metals Group 1A (except hydrogen)Group 1A (except hydrogen)

Alkaline earth metalsAlkaline earth metals Group 2AGroup 2A

Both alkali and alkaline earth metals areBoth alkali and alkaline earth metals arechemically reactivechemically reactive Alkali metals more reactivewhy do you think?Alkali metals more reactivewhy do you think?

Valence electronshow many do group 1A elements have?Valence electronshow many do group 1A elements have?

Is this stable?Is this stable?


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Transition ElementsTransition Elements

(Group B)(Group B)

2 categories2 categories

Transition metalsTransition metals

Inner Transition Metals (2 types)Inner Transition Metals (2 types)


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Inner Transition MetalsInner Transition Metals

Located along the bottom of the periodic tableLocated along the bottom of the periodic table

2 sets2 sets

Lanthanide seriesLanthanide series

Top row of the inner transition elementsTop row of the inner transition elements

These elements are used as phosphorsThese elements are used as phosphors

Substances that emit light when struck by electronsSubstances that emit light when struck by electrons

Where have we seen this before?Where have we seen this before?

Where do we see this today?Where do we see this today?

Actinide seriesActinide series

Bottom row of the inner transition elementsBottom row of the inner transition elements


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Transition elementsTransition elements

All other group B elements that are notAll other group B elements that are not

inner transition elementsinner transition elements

Basically the Group B elements we see onBasically the Group B elements we see onthe actual periodic tablethe actual periodic table

Think of it as the continental USThink of it as the continental US


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3 main classifications3 main classificationsof elementsof elements

MetalsMetals

NonmetalsNonmetalsMetalloidsMetalloids


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2. Nonmetals2. Nonmetals

Occupy the upper right side of the periodicOccupy the upper right side of the periodic

tabletable

Usually gasesUsually gases Brittle, dullBrittle, dull--looking solidslooking solids

Poor conductors of heat and electricityPoor conductors of heat and electricity

Bromine (Br) is the only nonmetal that isBromine (Br) is the only nonmetal that isliquid at room temperatureliquid at room temperature


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Important nonmetalsImportant nonmetals

Group 7AGroup 7A

HalogensHalogensHighly reactive elementsHighly reactive elements

What does this mean?What does this mean? Why are they highly reactive?Why are they highly reactive?

Look at the valence electronsLook at the valence electrons

Group 8AGroup 8A

Noble gasesNoble gasesHighly unreactiveHighly unreactive

Why?Why?

8 valence electrons8 valence electrons


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3 main classifications3 main classificationsof elementsof elements

MetalsMetalsNonmetalsNonmetals

MetalloidsMetalloids


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3. Metalloids3. Metalloids

Border the stairBorder the stair--case linecase line

Elements with physical and chemicalElements with physical and chemical

properties of both metals and nonproperties of both metals and non--metalsmetals

Silicon and germaniumSilicon and germanium

Two of the most important metalloidsTwo of the most important metalloids

Anyone know why?Anyone know why?

Used in computer chips and solar cellsUsed in computer chips and solar cells


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Everyday ExamplesEveryday Examples

Metals?Metals? JewelryJewelry

Pot and pansPot and pans

CarsCars

Nonmetals?Nonmetals? Air we breathAir we breath

NitrogenNitrogen

Neon signsNeon signs

diamondsdiamonds

Metalloids?Metalloids? Computer chipsComputer chips


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THANKS A TONNE.THANKS A TONNE.

RITESH KUMAR FATWANIRITESH KUMAR FATWANI

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periodic table hstry