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UNIT 3 Part 3: UNIT 3 Part 3: The Periodic Table The Periodic Table 1 Development of the Periodic 1 Development of the Periodic Table Table 2 Reading the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends 3 Periodic Trends

UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

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Page 1: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

UNIT 3 Part 3: UNIT 3 Part 3: The Periodic TableThe Periodic Table

1 Development of the Periodic Table1 Development of the Periodic Table2 Reading the Periodic Table2 Reading the Periodic Table

3 Periodic Trends 3 Periodic Trends

Page 2: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

1 Development of the Periodic 1 Development of the Periodic TableTable

Forerunners of the Periodic TableForerunners of the Periodic Table::

As Chemists and other scientists discovered As Chemists and other scientists discovered more and more Elements they needed a way more and more Elements they needed a way to keep track of them all. They need a method to keep track of them all. They need a method of organization. of organization.

Page 3: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

Döbereiner Döbereiner In the early 1800’s In the early 1800’s J.W. J.W.

DDööbereinerbereiner began classifying began classifying elements into groups of three elements into groups of three (TRIADS(TRIADS ). ). The elements within the The elements within the triads share similar chemical triads share similar chemical propertiesproperties..

Ex:, lithium, sodium and potassium; Ex:, lithium, sodium and potassium; calcium, strontium and barium; AND calcium, strontium and barium; AND chlorine, bromine, and iodine are three chlorine, bromine, and iodine are three sets of triadssets of triads

Page 4: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

Newlands Newlands Then in 1865, Then in 1865, J.A.RJ.A.R NewlandsNewlands

noticed that noticed that when the known when the known elements were arranged in elements were arranged in increasing atomic mass, regular , regular patterns would occur, AND they patterns would occur, AND they would repeat would repeat every 8 elements ((law of octaveslaw of octaves).).

C

Page 5: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

Mendeleev & Meyer Mendeleev & Meyer In 1869, In 1869, Dmitri MendeleevDmitri Mendeleev and and

Lothar MeyerLothar Meyer independently independently published practically identical published practically identical schemes for classifying elementsschemes for classifying elements. . MendeleevMendeleev also noticed regular also noticed regular patterns in the elements when they patterns in the elements when they were were arranged by increasing atomic arranged by increasing atomic massmass. He produced the first periodic . He produced the first periodic table of elements and table of elements and actually left actually left spaced to be filled in by spaced to be filled in by undiscovered elementsundiscovered elements. He was . He was able to predict there would be more able to predict there would be more and about where they would go!and about where they would go!

Page 6: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

Mendeleev's Periodic Table of the Elements

Page 7: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

Periodic LawPeriodic Law & Moseley & Moseley The periodic table Mendeleev The periodic table Mendeleev

came up with was a good start came up with was a good start but it wasn’t perfect. It wasn’t but it wasn’t perfect. It wasn’t until until 19131913 when when H.G.J. Moseley H.G.J. Moseley determined that the correct way determined that the correct way to organize the periodic table is to organize the periodic table is by by ATOMIC NUMBER. The . The PERIODIC LAW- when elements when elements are are arranged in order of increasing atomic number, their physical and chemical properties show a periodic pattern.

Increases in atomic #

Page 8: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

2 Reading the Periodic Table2 Reading the Periodic TableOrganizing the SquaresOrganizing the Squares::

When you look at the modern Periodic Table of When you look at the modern Periodic Table of Elements (PTE) you will notice it is Elements (PTE) you will notice it is arranged in to arranged in to columnscolumns (vertically)(vertically) and rowsand rows (horizontally)(horizontally). The . The columns are called GROUPS or FAMILIEScolumns are called GROUPS or FAMILIES (18)(18). . The rows are called PERIODSThe rows are called PERIODS (7)(7)..

Periods Groups

Page 9: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

Labeling & Naming GroupsLabeling & Naming Groups

There are There are 3 methods for numbering3 methods for numbering the the columnscolumns (the American, the European and the IUPAC)(the American, the European and the IUPAC) The only 2 your The only 2 your book uses is the American and the IUPAC.book uses is the American and the IUPAC. AMERICAN: 1A, 2A, 3B-8B, 11B, 12B, 3A-8AAMERICAN: 1A, 2A, 3B-8B, 11B, 12B, 3A-8A IUPAC: 1-18IUPAC: 1-18

The The families are given namesfamilies are given names:: 1A- ALKALI METALS 1A- ALKALI METALS (except hydrogen)(except hydrogen)

2A-ALKALINE EARTH METALS2A-ALKALINE EARTH METALS 7A- HALOGENS7A- HALOGENS 8A- NOBLE GASES8A- NOBLE GASES aka: inert or inactive gases

Page 10: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

Metals, Nonmetals and Metals, Nonmetals and SemimetalsSemimetals

Metals comprise the comprise the majority of the elementsmajority of the elements on the on the periodic table. periodic table. CommonlyCommonly they they are solidsare solids (except Hg),(except Hg), malleablemalleable, , conductorsconductors of heat and electricity, and are of heat and electricity, and are ductileductile. Also they have other specific physical properties . Also they have other specific physical properties such as luster or shine.such as luster or shine.

Nonmetals comprise the comprise the second largest type of second largest type of elementselements on the PTE. Many are also on the PTE. Many are also gases at room gases at room temperaturetemperature (except bromine)(except bromine), which is a liquid., which is a liquid.

Semimetals (metalloids) have have propertiesproperties which are which are like like metals but also like nonmetalsmetals but also like nonmetals. Theses comprise the . Theses comprise the smallest group on the PTEsmallest group on the PTE..

Page 11: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

Electronic Configuration & the Electronic Configuration & the PTEPTE::

The The electronselectrons in the in the outermost energy outermost energy levellevel are called the are called the VALENCEVALENCE electrons electrons. . These are the electrons which will These are the electrons which will allow one allow one

atom to interact with another atom andatom to interact with another atom and are are responsible forresponsible for the elements the elements chemical chemical propertiesproperties. .

The The members in each group/family have the same # of valence electron and that is why they share similar chemical properties..

Page 12: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

The s-, p-, d- and f-block The s-, p-, d- and f-block ElementsElements::

S-BLOCK- S-BLOCK- groups 1&2groups 1&2

P-BLOCK- P-BLOCK- groups 13-18groups 13-18

D-BLOCK- D-BLOCK- groups 3-12groups 3-12 AKA: transition metals AKA: transition metals F-BLOCK- F-BLOCK- the lanthanide & actinide seriesthe lanthanide & actinide series AKA: the inner transition AKA: the inner transition

metalsmetals

S p

d

f

Page 13: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

3 Periodic Trends3 Periodic Trends

As you As you move across the periodic tablemove across the periodic table you you begin to begin to see trends/predictable patternssee trends/predictable patterns in in the the chemical and physical propertieschemical and physical properties of the of the elements. This phenomenon is known as elements. This phenomenon is known as

PERIODIC TRENDSPERIODIC TRENDS..

Page 14: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

Atomic RadiusAtomic Radius

Atoms have a radius called the ATOMIC Atoms have a radius called the ATOMIC RADIUSRADIUS- - the distance from the center of the atom to the distance from the center of the atom to the farthest most/ highest energy level. This distance is the farthest most/ highest energy level. This distance is not exact.not exact. We estimate.We estimate.

Contrary to popular opinion… Contrary to popular opinion… atoms with more atoms with more electrons electrons do not alwaysdo not always have a larger atomic have a larger atomic radiusradius. The trend is:. The trend is: As you move As you move from from TOP to BOTTOMTOP to BOTTOM down the PTE down the PTE

the radius grows largerthe radius grows larger As you move As you move from from RIGHT to LEFTRIGHT to LEFT across the PTE across the PTE

the radius grows largerthe radius grows larger

Page 15: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

ATOMIC RADIIATOMIC RADII

Largest

Page 16: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

The first trend has a simple explanation: The first trend has a simple explanation: as you as you move down through a group/family you are move down through a group/family you are actually adding additional principle quantum actually adding additional principle quantum numbersnumbers (ex group 1: (ex group 1: 11s, s, 22s, s, 33s, s, 44s, s, 55s, s, 66s, and s, and 77s)s) with with corresponding increases in the number of corresponding increases in the number of electrons from 1, 3, 11, 19, 37, 55, and 87. Ergo electrons from 1, 3, 11, 19, 37, 55, and 87. Ergo the radius must increase to accommodate these the radius must increase to accommodate these increases in electronsincreases in electrons..

The second trend is more complex. The second trend is more complex. As you As you move across a move across a periodperiod you are increasing both you are increasing both the # of electrons the # of electrons as well asas well as the number of the number of protonsprotons. . This allows the protons to pull more strongly on the electrons in the in the same energy same energy levellevel thus thus shrinking the radius..

Page 17: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

Ionic SizeIonic Size

We know atoms can gain or lose electron to We know atoms can gain or lose electron to form Ions. Depending whether they gain form Ions. Depending whether they gain (becoming (becoming

negatively charged)negatively charged) or lose or lose (becoming positively charged)(becoming positively charged) will will depend on whether ionic size will shrink or grow.depend on whether ionic size will shrink or grow.

When you gain electrons- the ionic size growsWhen you gain electrons- the ionic size grows As you lose electrons- the ionic size shrinksAs you lose electrons- the ionic size shrinks ((more more

protons pulling on fewer electrons= shrinkingprotons pulling on fewer electrons= shrinking)). . The trend is complex- Figure 5-17 p.176The trend is complex- Figure 5-17 p.176

Page 18: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

Ionization EnergyIonization Energy

The energy needed to strip an atom of an The energy needed to strip an atom of an electron is called IONIZATION ENERGYelectron is called IONIZATION ENERGY. . Typically Typically measured in J/atommeasured in J/atom you can think of it you can think of it as a measure of how strongly the atom holds on as a measure of how strongly the atom holds on to its valence electrons.to its valence electrons.

Its Its trend is exactly opposite the atomic radius trend is exactly opposite the atomic radius trendtrend:: As you move from As you move from BOTTOM to TOPBOTTOM to TOP the ionization the ionization

energy energy increasesincreases As you move from As you move from LEFT to RIGHTLEFT to RIGHT the ionization the ionization

energy energy increasesincreases

Page 19: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

Ionization EnergyIonization Energy

Hardest

Easiest

Page 20: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

Successive Ionization EnergiesSuccessive Ionization Energies

What if you want to pull more than one electron from What if you want to pull more than one electron from an atom? What happens to the ionization energy an atom? What happens to the ionization energy for the 2nd, 3rd, or even 4th electron?for the 2nd, 3rd, or even 4th electron?

Successive ionization energies refer to the energy Successive ionization energies refer to the energy required to remove the 2nd, 3rd and more required to remove the 2nd, 3rd and more electronselectrons. . The energy required increasesThe energy required increases, , partially partially because of electron-electron repulsionbecause of electron-electron repulsion, however it , however it is not a linear increase. is not a linear increase. Examine figure 5-20 p.180Examine figure 5-20 p.180 *note* there is always a dramatic increase in ionization *note* there is always a dramatic increase in ionization

energy when you start extracting electrons from the inner energy when you start extracting electrons from the inner noble gas core.noble gas core.

Page 21: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

Electron AffinityElectron Affinity

If you can pull an electron from an atom… you If you can pull an electron from an atom… you can ADD one to an atom. can ADD one to an atom. When an When an atom gains atom gains an electron energy is REQUIREDan electron energy is REQUIRED! They are ! They are reported in reported in J/molJ/mol (NOT ATOMS)(NOT ATOMS). Not all energy . Not all energy used in the addition of an electron is gained by used in the addition of an electron is gained by the atom that the electron is being added to. the atom that the electron is being added to. It It is possible to have + and – electron affinitiesis possible to have + and – electron affinities. If . If the value is the value is + then the atom gaining the electron + then the atom gaining the electron is also gaining energyis also gaining energy. If the value is . If the value is – then the – then the atom gaining the electron is releasing energyatom gaining the electron is releasing energy..

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General ruleGeneral rule for the electron affinity trend- for the electron affinity trend-NonmetalsNonmetals have have more NEGATIVE electron more NEGATIVE electron

affinities than the metalsaffinities than the metals..The The exceptionexception is the is the noble gasesnoble gases..

** OCTET RULE** atoms tend to gain, lose or even share electrons in order to have a full set of valence electrons (8)- to have a full s and p orbital..

More Negative

Page 23: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

ElectronegativityElectronegativity

This is This is the ability of an atom to attract an the ability of an atom to attract an electron in a chemical bondelectron in a chemical bond. This is a . This is a unit lessunit less value.value.

The The least electronegative elements are in the least electronegative elements are in the LOWER LEFT CORNERLOWER LEFT CORNER of the PTE. The trend of the PTE. The trend is the same as Ionization energy.is the same as Ionization energy.

When bonds occur… When bonds occur… the atom with the higher the atom with the higher electronegativity would attract the electron more electronegativity would attract the electron more stronglystrongly. Depending on the discrepancy of the . Depending on the discrepancy of the attraction there will form different types of bonds attraction there will form different types of bonds (Ch7).(Ch7).

Page 24: UNIT 3 Part 3: The Periodic Table 1 Development of the Periodic Table 2 Reading the Periodic Table 3 Periodic Trends

More electronegative

http://www.tutor-homework.com/Chemistry_Help/electronegativity_table/electronegativity.html