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Chapter 3: Atoms & ElementsChapter 3: Atoms & Elements

Mixtures & Pure SubstancesMixtures & Pure Substances

Elements & SymbolsElements & Symbols

The Periodic TableThe Periodic Table

Atomic StructureAtomic Structure

IsotopesIsotopes

Electron Energy LevelsElectron Energy Levels

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Classification of matterClassification of matter

MatterMatter

Pure Substance Mixture

Element Compound

FeFe FeSFeS

MgMg MgOMgO Mg + OMg + O22

Fe + SFe + S

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Pizza

MixtureMixture

HomogeneousHomogeneous (Solution)(Solution)

HeterogeneousHeterogeneous

Fe + SFe + S

MixturesMixtures

NNoonn--uunniiffoorrmm ccoommppoossiittiioonnUniform compositionUniform composition

Air

UrineGasoline

Sand

Tea w/ice

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VIIIA

Each element is assigned a unique symbolEach element is assigned a unique symbol1-2 letters; 1st is capitalized1-2 letters; 1st is capitalized

Atomic SymbolsAtomic Symbols

BromineNickel

HydrogenNitrogen

Aluminum

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Copper (Cuprum) CuGold (Aurum) AuIron (Ferrum) FeLead (Plumbum) PbMercury (Hydrargyrum) HgPotassium (Kalium) KSilver (Argentum) AgSodium (Natrium) NaTin (Stannum) SnTungsten (Wolfram) W

Atomic SymbolsAtomic SymbolsSome of the elements whose symbols are derived from other languages

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VIIIA

Elements with same starting letter, get Elements with same starting letter, get second letter added to the symbolsecond letter added to the symbol

ChlorineChromium

Calcium

Carbon

Cobalt Copper (Cu)

Atomic SymbolsAtomic Symbols

B

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Periodic Table: Groups (Families)Periodic Table: Groups (Families)

H

Li

Na

Cs

Rb

K

TlHgAuHfLsBa

Fr

PtIrOsReWTa

He

RnAtPoBiPb

Be

Mg

Sr

Ca

CdAgZrY PdRhRuTcMoNb

AcRa

ZnCuTiSc NiCoFeMnCrV

In XeITeSbSn

Ga KrBrSeAsGe

Al ArClSPSi

B NeFONC

I A

III B IVB V B VIB VIIB VIII B IB IIB

Gd

Cm

Tb

Bk

Sm

Pu

Eu

Am

Nd

U

Pm

Np

Ce

Th

Pr

Pa

Yb

No

Lu

Lr

Er

Fm

Tm

Md

Dy

Cf

Ho

Es

Alkali Metals (exclude H) Alkali Metals (exclude H)

Alkali Metals (exclude H) Alkali Metals (exclude H)

Alkaline Earth MetalsAlkaline Earth MetalsAlkaline Earth MetalsAlkaline Earth Metals Halogens Halogens

Halogens Halogens

Noble (Inert) gases Noble (Inert) gases

Noble (Inert) gases Noble (Inert) gases

III A IV A V A VI A VIIA

VIIIA

II A

Transition Metals Transition Metals

Transition Metals Transition Metals

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He

Rn

XeI

KrBrSe

ArClS

NeFO

P

NC

H

Li

Na

Cs

Rb

K

TlHgAuHfLsBa

Fr

PtIrOsReWTa PoBiPb

Be

Mg

Sr

Ca

CdAgZrY PdRhRuTcMoNb

AcRa

ZnCuTiSc NiCoFeMnCrV

In SbSn

Ga Ge

Al

Gd

Cm

Tb

Bk

Sm

Pu

Eu

Am

Nd

U

Pm

Np

Ce

Th

Pr

Pa

Yb

No

Lu

Lr

Er

Fm

Tm

Md

Dy

Cf

Ho

Es

At

Te

As

Si

B

1

2

3

4

5

6

7

Periods areassigned numbers

Periods areassigned numbers

Periodic Table: PeriodsPeriodic Table: Periods

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At

Te

As

Si

B

He

Rn

XeI

KrBrSe

ArClS

NeFO

P

NC

H

Li

Na

Cs

Rb

K

TlHgAuHfLsBa

Fr

PtIrOsReWTa PoBiPb

Be

Mg

Sr

Ca

CdAgZrY PdRhRuTcMoNb

AcRa

ZnCuTiSc NiCoFeMnCrV

In SbSn

Ga Ge

Al

Gd

Cm

Tb

Bk

Sm

Pu

Eu

Am

Nd

U

Pm

Np

Ce

Th

Pr

Pa

Yb

No

Lu

Lr

Er

Fm

Tm

Md

Dy

Cf

Ho

Es

MetalsMetalsMetalsMetals LustrousLustrous, , malleablemalleable and and ductileductile..

ConductorsConductors (heat & electricity) (heat & electricity)

SolidsSolids at room temp at room temp (except Hg)(except Hg)

Lose electronsLose electrons to non-metals. to non-metals.

LustrousLustrous, , malleablemalleable and and ductileductile..

ConductorsConductors (heat & electricity) (heat & electricity)

SolidsSolids at room temp at room temp (except Hg)(except Hg)

Lose electronsLose electrons to non-metals. to non-metals.

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HeHe

RnRn

XeXeII

KrKrBrBrSeSe

ArArClClSS

NeNeFFOO

PP

NNCC

H

Li

Na

Cs

Rb

K

TlHgAuHfLsBa

Fr

PtIrOsReWTa PoBiPb

Be

Mg

Sr

Ca

CdAgZrY PdRhRuTcMoNb

AcRa

ZnCuTiSc NiCoFeMnCrV

In SbSn

Ga Ge

Al

Gd

Cm

Tb

Bk

Sm

Pu

Eu

Am

Nd

U

Pm

Np

Ce

Th

Pr

Pa

Yb

No

Lu

Lr

Er

Fm

Tm

Md

Dy

Cf

Ho

Es

At

Te

As

Si

B

Non-metalsNon-metalsNon-metalsNon-metals

GasGas, liquidliquid, solid (dull, brittle)solid (dull, brittle)

Poor conductors = Insulators

Many are diatomic molecules.

Gain e’s from metals

Share e’s with other non-metals

GasGas, liquidliquid, solid (dull, brittle)solid (dull, brittle)

Poor conductors = Insulators

Many are diatomic molecules.

Gain e’s from metals

Share e’s with other non-metals

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He

Rn

XeI

KrBrSe

ArClS

NeFO

P

NC

H

Li

Na

Cs

Rb

K

TlHgAuHfLsBa

Fr

PtIrOsReWTa PoBiPb

Be

Mg

Sr

Ca

CdAgZrY PdRhRuTcMoNb

AcRa

ZnCuTiSc NiCoFeMnCrV

In SbSn

Ga Ge

Al

Gd

Cm

Tb

Bk

Sm

Pu

Eu

Am

Nd

U

Pm

Np

Ce

Th

Pr

Pa

Yb

No

Lu

Lr

Er

Fm

Tm

Md

Dy

Cf

Ho

Es

At

Te

As

Si

B

MetalloidsMetalloidsMetalloidsMetalloids

Intermediate propertiesIntermediate properties

Semi conductors

Intermediate propertiesIntermediate properties

Semi conductors

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H

Li

Na

Cs

Rb

K

TlHgAuHfLsBa

Fr

PtIrOsReWTa PoBiPb

Be

Mg

Sr

Ca

CdAgZrY PdRhRuTcMoNb

AcRa

ZnCuTiSc NiCoFeMnCrV

In Sn

Ga

Al

Gd

Cm

Tb

Bk

Sm

Pu

Eu

Am

Nd

U

Pm

Np

Ce

Th

Pr

Pa

Yb

No

Lu

Lr

Er

Fm

Tm

Md

Dy

Cf

Ho

Es

HeHe

RnRn

XeXeII

KrKrBrBrSeSe

ArArClClSS

NeNeFFOO

PP

NNCC

Sb

Ge

At

Te

As

Si

B

MetalloidsMetalloidsMetalloidsMetalloids

MetalsMetalsMetalsMetals Non-metalsNon-metalsNon-metalsNon-metals

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A model of matterA model of matter

AtomAtom - The smallest unit of an element that is still that element.

MoleculeMolecule -The smallest unit of a pure substance that is still that substance.

May contain > 1 atom or elementMay contain > 1 atom or element.

ie. Aluminum (Al)ie. Aluminum (Al)

ie. Water (Hie. Water (H22O)O)

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& neutronsneutrons

Structure of the atomStructure of the atom Nucleus = Nucleus =

Small, dense, ++ charge in the center of an atom.

contains

protonsprotons ++

++

++++

++ ++

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Structure of the atomStructure of the atom NucleusNucleus

ElectronsElectrons

-- charged particles that surround the nucleus.

ElectronsElectrons move around nucleusnucleus in orbitalsorbitals.

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Structure of the atomStructure of the atom

The nucleusnucleus is a small part of an atom.

If the nucleus was the sizeof a marble, the atom wouldfill a football stadium.

If the nucleus was the sizeof a marble, the atom wouldfill a football stadium.

The nucleus would weighover 10,000 tons.The nucleus would weighover 10,000 tons.

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The atomic symbolThe atomic symbol

XAA

ZZ

A A = Mass number (amu)

= # protons# protons ++ # neutrons# neutrons

ZZ = Atomic number

= # protons# protons = # electrons# electrons

++++

++++

++ ++

--

--

------

--

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The atomic symbolThe atomic symbol

X1212

66

A A = Mass number

= # protons# protons ++ # neutrons# neutrons

ZZ = Atomic number

= # protons# protons = # electrons# electrons

++++

++++

++ ++

--

--

------

--

6 6

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The atomic symbolThe atomic symbol

CC1212

66

A A = Mass number

= # protons# protons ++ # neutrons# neutrons

ZZ = Atomic number

= # protons# protons = # electrons# electrons

++++

++++

++ ++

--

--

------

--

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The atomic symbolThe atomic symbol

Na2323

1111

A A = Mass # = p + n = 23

ZZ = Atomic # = p = 11

SodiumSodium

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Ag107.87

Silver47 Atomic number

Name of the element

Elemental Symbol

Atomic mass (weight)Atomic mass (weight)

Atomic weightAtomic weight = The averageaverage, relative mass of an atom in an element.

Why is the atomic weight on the tables not a whole #?

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Isotopes of HydrogenIsotopes of HydrogenIsotopes =Isotopes = Atoms of the same element but

having different masses.

11

21

31

++

H H H

++

--++

--

Protium99.99%99.99%

Deuterium0.01%0.01%

TritiumTrace %Trace %

--

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Isotopes of HydrogenIsotopes of HydrogenIsotopes =Isotopes = Atoms of the same element but

having different masses.

11

21

31

++

H H H

--

++

--++

--

Average Atomic weightAverage Atomic weight of Hydrogen = 1.007941.00794 amuamu

H-1 or Hydrogen-1H-1 or Hydrogen-1 H-2 or Hydrogen-2H-2 or Hydrogen-2 H-3 or Hydrogen-3H-3 or Hydrogen-3

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++++

++++

++ ++

Isotopes of CarbonIsotopes of Carbon

--

Average Atomic weightAverage Atomic weight of C= 12.01112.011 amuamu

98.89%98.89%

CC661212 CC66

1313CC66

1414

++++

++++

++ ++

--

1.11%1.11%

++++

++++

++ ++

--

Trace %Trace %

--

--

--

---- --

--

-- --

--

--

--

----

--

C-12 or Carbon-12C-12 or Carbon-12 C-13 or Carbon-13C-13 or Carbon-13 C-14 or Carbon-14C-14 or Carbon-14

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Radioactive IsotopesRadioactive Isotopes

CC661414

++++

++++

++ ++

--

--

--

----

--

31

++

H

--

Nucleus is unstableSo falls apart (decays)

Giving radioactive particles

Nucleus is unstableSo falls apart (decays)

Giving radioactive particles

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The atomic symbol & isotopesThe atomic symbol & isotopes

Determine the number of protons, neutrons and electrons in each of the following.

PP31311515 BaBa

138138 5656 UU

238238 9292

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Atomic StructureAtomic Structure

Symbol At# Mass P N eSymbol At# Mass P N e––

____ ____ ____ 4 5 ___

Cl ____ 37 ___ ___ ___

Si ____ ____ ___ 14 ___

BeBe 44 9 9 44

1717 1717 20 1720 17

1414 28 28 1414 1414

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Electron arrangementElectron arrangement

2288

18183232

Electronsfill layers

around nucleusLow High

Electronsfill layers

around nucleusLow High

Shells = Energy levelsShells = Energy levels

2424

1212MgMg

A new layer isadded for each row or period in the table.

A new layer isadded for each row or period in the table.

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11

11HH

77

33LiLi

44

22HeHe

IAIA IIAIIA

99

44BeBe

31

1111

55 BB

11

11HH

77

33LiLi

IAIA IIAIIA IIIAIIIA

99

44BeBe

32

1111

55 BB1212

66 CC1313

77 NN

IIIAIIIA IVAIVA VAVA

33

11

11HH

77

33LiLi

44

22HeHe

99

44BeBe 2020

1010NeNe

2323

1111NaNa

2424

1212MgMg4040

1818ArAr

IAIA IIAIIA VIIIAVIIIA

34

3333

2424

1212MgMg

11

11HH

77

33LiLi

2323

1111NaNa

99

44BeBe 1111

55 BB

2727

1313AlAl

Valence electronsValence electronsWhere most chemical

Reactions occur.

1111

2222

Inner electronsInner electrons: No reactions if normal conditions.Inner electronsInner electrons: No reactions if normal conditions.

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Inner vs. valence electronsInner vs. valence electrons

Valence electronsValence electronsThis is wheremost chemicalreactionsoccur.

Inner electronsInner electronsNot much happenshere under normalconditions.

With added energy inner electrons jump toWith added energy inner electrons jump to higher levels, then fall back giving Ehigher levels, then fall back giving E

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11

11HH

77

33LiLi

44

22HeHe

99

44BeBe 2020

1010NeNe

2323

1111NaNa

2424

1212MgMg4040

1818ArAr

88881111

2222

37

11

11HH

77

33LiLi

2323

1111NaNa

Lewis StructuresLewis Structures

Show only Valence

Electrons

H

Li

Na

K