Periodic table e

77
the Periodic table of elements MODULE 4: MATTER AND MATERIALS

Transcript of Periodic table e

the Periodic table of elements

MODULE 4: MATTER AND MATERIALS

History of the Periodic TableAristotle’s Classical Elements

Earth Fire Water Air

History of the Periodic TableAristotle’s Classical Elements

Earth: • Cold and dry • Solids Water: • Cold and wet • Liquids

Air: • Hot and wet • Gases Fire: • Hot and dry • Plasma &

heat Aether: • Heavenly Bodies

Fun with the Periodic TableClassical Periodic Table

History of the Periodic TableAntoine Laurent Lavoisier

Wrote the first chemistry textbook• 1789• Elementery Treatise of

Chemistry Contained a list of 33

elements• Included caloric and

light

History of the Periodic TableJohann Wolfgang Döbereiner

Formulated the law of triads• 1828• Grouped the elements

in groups of three with the same properties

• Br, Cl and I• Ca, Ba, Sr

History of the Periodic TableAlexandre-Emile de Chancortois

1862 Wrote the elements on a piece

of ribbon Ordered elements by atomic

weight Rolled ribbon into a cylinder with

16 units circumference Noticed that elements with

similar properties were aligned vertically

Called it the “telluric helix”

History of the Periodic TableAlexandre-Emile de Chancortois

History of the Periodic TableAlexandre-Emile de ChancortoisModern day Telluric Helix: Alexandre Arrangement

History of the Periodic TableJohn Newlands

Formulated the Law of Octaves• 1863• Ordered elements by atomic

weight• Noticed that properties repeated

every 8 elements

History of the Periodic TableJohn Newlands

Law of octaves fail beyond Calcium• Why?

John Newlands was told that his arrangement was as arbitrary as arranging the elements alphabetically

and his paper was rejected for publication

History of the Periodic TableDmitri Mendeleev

Published the first version of the periodic table• 1869• Contained 56 elements

arranged according to atomic masses

• Predicted the existence and properties of unknown elements

Formulated the periodic law

History of the Periodic TableDmitri Mendeleev

“I saw in a dream a table where all the elements fell into place as required. Awakening, I immediately

wrote it down on a piece of paper” – Dimitri Mendeleev

History of the Periodic TableProblems with Mendeleev’s Table

Sb51

121,76

Te52

127,60

I53

126,91

Ar18

39,95

K19

39,10

Ca20

40,08

“Corrected” the atomic weights if it caused the element to be placed in the wrong group• Assumed that weights

were determined incorrectly due to lack of technology

History of the Periodic TableMendeleev’s Predictions

Property Eka-aluminium GalliumAtomic mass 68 69.72

Density (g/cm³) 6.0 5.904Melting Point (°C) Low 29.78

Oxide's Formula

Ea2O3 (density: 5.5 g/cm³)

(soluble in both alkalis and acids)

Ga2O3 (density: 5.88 g/cm³)

(soluble in both alkalis and acids)

Chloride's Formula Ea2Cl6 (volatile) Ga2Cl6 (volatile)

History of the Periodic TableHenry Mosely

Recognised relationship between x-ray wavelength and nuclear charge• 1914• Rearranged elements

according to nuclear charge• Showed gaps in Mendeleev’s

table at atomic numbers 43 and 6

Also predicted new elements

History of the Periodic TableHenry Mosely

Was sent to serve as foot soldier in WWI before his research was finished

Was killed by a snipers bullet

Britain now assign non-combat duties to their scientists during war time

History of the Periodic TableGlenn T. Seaborg

Co-discovered 10 new elements

In 1944 he moved the actanoids out of the main body of the periodic table to its current position

History of the Periodic TableGlenn T. Seaborg

“This is the greatest honour ever bestowed

upon me – greater even, I think, than winning the

Nobel Prize.” – Glenn T. Seaborg

Fun with the Periodic TableModern Alchemists Version

Fun with the Periodic TablePhillip Steward’s Chemical Galaxy

Fun with the Periodic TableMyan Periodic Table

Fun with the Periodic TableMarshall W. Cronyn: Appropriate

place for Hydrogen

Fun with the Periodic TablePeriodic Table Monument: Universtiy

of Technology, Bratislavia

Fun with the Periodic TableCyclical Continuum of Chemical Properties

Fun with the Periodic TableJanet form Periodic Table

Fun with the Periodic TablePeriodic Table Cartograms

Fun with the Periodic TableWorlds Smallest Periodic Table

Fun with the Periodic Table2012 IUPAC Periodic Table

Fun with the Periodic TableTheodore Grey’s Photographic

Periodic Table

Fun with the Periodic TablePeriodic Table of Cupcakes

Fun with the Periodic TableFunny Periodic Table

Fun with the Periodic TableChuck Norris Periodic Table

Fun with the Periodic Table3D Periodic Table

Pyramid

Fun with the Periodic TableCorning Museum of Glass Periodic

Table Display

Fun with the Periodic TableChocolate Periodic Table

Fun with the Periodic TableElements Discovery by Year

Periodic TableStructure

I

Vertical Columns:• Groups• Exhibit the same Chemical

Properties

Periodic TableStructure

Horizontal Rows:• Periods• Chemical properties vary across

the periods• Each Period represents a new

energy level

Periodic TableStructure

s-block

Periodic TableStructure

d-block

Periodic TableStructure

p-block

Periodic TableStructure

f-block

Periodic TableStructure

I

Group I:• Alkali Metals• React violently with water to

form an alkaline solution• Have one valence electron• Valence = 1

Periodic TableStructure

Group II:• Alkaline earth Metals• React violently with water to

form an alkaline solution• Occur abundantly in the earths

crust• Have two valence electrons• Valence = 2

III

Periodic TableStructure

Transition metals:• Elements with an

incomplete d-subshell

• Can form cations with incomplete d-subshells

Periodic TableStructure

Group III:• Have three valence

electrons• Valence = 3

III III

Periodic TableStructure

III III IV

Group IV:• Have four valence

electrons• Valence = 4

Periodic TableStructure

III III IV V

Group V:• Have five valence

electrons• Valence = 3

Periodic TableStructure

Group VI:• Chalcogens• S, Se and Te are commonly

found in copper ore• Has six valence electrons• Valene = 2

I

II III IV V VI

Periodic TableStructure

Group VII:• Halogens• React with metals to form

salts• Has seven valence electrons• Valence = 1

I

II III IV V VIVII

Periodic TableStructure

Group VIII:• Noble Gasses• Rare and Inert• Have eight valence electrons• Valence = 0

I

II III IV V VIVII

VIII

Lanthanides:• Rare earth elements• Form cations with charge +3

I

II III IV V VIVII

VIII

Periodic TableStructure

Actanides:• Radio active• Mostly synthetic

I

II III IV V VIVII

VIII

Periodic TableStructure

I

II III IV V VIVII

VIII

Periodic TableStructure

Metals

I

II III IV V VIVII

VIII

Periodic TableStructure

Semi-metals

I

II III IV V VIVII

VIII

Periodic TableStructure

Non-metals

PeriodicityDefinition

The chemical and physical properties of elements• Change from left to right across a period • Change from top to bottom in a group• Similarities between the properties of elements in

the same group Periodicity:

• The periodic variation in the properties of elements as one moves from left to right and from top to bottom in the periodic table

Atom radius

Increase

Decrease from left to right (increase from right to left)

Increase from top to bottom

Periodicity

Atom radius: DefinitionThe distance between the nucleus and the outer most stable orbital

Periodicity

Atom radius: Left to Right Decrease from left to right

• Atom number increase• Number of protons, and therefore the nucleus

charge, increase• Electrons are added to the same principal energy

level• Electrons are more strongly attracted to the

nucleus

3p+

e-

5p+e-

e-

e-4p+e-

e-

Periodicity

Atom radius: Top to Bottom Increase from top to bottom

• A new energy level is added• The outer electrons are further away from the

nucleus• Inner electrons shield the outer electrons from

the nucleus (screening effect)• Electrons are attracted by the nucleus less

strongly• Atom radius decrease

Periodicity

2p+e- e-4p+e- e- e-e- 12p+e- e- e-

e-e-

e-

e-e-

e-e-

e-e-

PeriodisiteitAtoom radius: Bo na Onder

Screening Effect

12p+e- e- e-

e-e-

e-

e-e-

e-e-

e-e-

e-

e-

Outer e- attracted by nucleus

Outer e- repelled by inner e-

Experience a smaller net attractive force

Inner e- “shields” outer e- from nucleus

Periodicity

PeriodicityIonization energy

The energy required to remove an electron from an atom

12p+e- e- e-

e-e-

e-

e-e-

e-e-

e-

e-

MgMg+

Increases from left to right Decreases from top to bottom

Increase

PeriodicityIonization energy

PeriodicityIonization energy: Left to right Increase from left to right

• Atom number increase• Number of protons, and therefore the nucleus

charge, increase• Electrons are added to the same principal energy

level• Electrons are more strongly attracted to the

nucleus• More energy required to remove electrons

PeriodicityIonization energy: Top to Bottom Decrease from top to bottom

• A new energy level is added• The outer electrons are further away from the

nucleus• Inner electrons shield the outer electrons from

the nucleus (screening effect)• Electrons are attracted by the nucleus less

strongly• Less energey required to remove electron

Borons ionization energy is less than that of Beryllium• Be: S-orbital completely filled• B: A single electron in the p-orbital• Electrons in the p-orbital has more energy than

elcetrons in s-ornitals• Less energy required to remove electron

PeriodicityIonization Energy: Deviations

Oxygen has a lower ionization energy than Nitrogen• N: One electron in each p-orbital• O: The first p-orbital contains an electron pair• Electrons in the same orbital repel eachother• Less energy required to remove electron

PeriodicityIonization energy: Deviations