Periodic TablePeriodic TableReview ActivityReview Activity

DefinitionDefinition

What does PERIODIC mean? A repeating pattern

Mendeleev left some spaces in his table because not all elements lined up according to atomic mass. He used info he knew about surrounding elements to PREDICT properties and masses of unknown elements.

How about that!

Mendeleev (1869)Mendeleev (1869)Organized table by...ATOMIC MASS

Thought pattern must exist between all elementsElements in columns show similar properties…Both physical and chemical!

Predicted properties of “missing” elements

Moseley (c. 1914)Moseley (c. 1914)rearranged table by ...ATOMIC NUMBER

Determined atomic number of elements by determining number of protons in element

Seaborg (1944)Seaborg (1944)Rearranged Periodic Table with...Lanthanide and Actinide Series pulled out/separated from main Periodic Table

Discovered countless isotopes & 10 new elements

Information from Information from Periodic TablePeriodic Table

Atomic numberChemical symbolAtomic massChemical name

Plus countless other information, depending on the table used!

Columns of Table = Columns of Table = groupsgroups or or familiesfamilies

Newer designation: 1-188 main families labeled with Roman Numeral and letter ‘A ’Elements within the same family have similar but not identical propertiesElectron configuration varies periodically (pattern of valence electrons)

family # 1-2-13-14-15-16-17-18or IA-IIA-IIIA-IVA-VA-VIA-VIIA-VIIIA

valence e- 1-2-3-4-5-6-7-8

1 2

13

141516

17

18

GROUPS/FAMILIES GIVES GROUPS/FAMILIES GIVES # VALENCE E-# VALENCE E-

DefinitionDefinitionValence electronselectrons found in the outermost energy level

use the group number to determine number of valence electrons

Names of FamiliesNames of FamiliesGroup 1 or IAGroup 2 or IIAGroup13 or IIIAGroup 14 or IVAGroup 15 or VAGroup 16 or VIAGroup 17 or VIIAGroup 18 or VIIIAGroups 3-12Lanthanide & Actinide series

Alkali metalsAlkaline Earth metalsBoron familyCarbon familyNitrogen familyChalogensHalogensNoble gasesTransition metalsInner transition metals

Rows of Table = Rows of Table = periodsperiods

Properties are not alike within a period7 periods = number of energy levels in atom2 additional rows at bottom of table are Lanthanide and Actinide series and belong to periods 6 and 7

7654321

PERIOD = # ENERGY LEVELSPERIOD = # ENERGY LEVELS

TrendsTrendsValence numberCharge of ionTendency to gain or lose electronsAtomic size (radius)Ionization energyElectron affinityElectronegativityReactivityMetallic vs. nonmetallic properties

PeriodicPeriodicLawLaw

The physical and chemical properties of the elements are periodic functions of their atomic number.

The tendency of atoms to gain or lose electrons so they acquire 8 electrons in their outer energy level for stability

Octet Octet RuleRule

Ionization Ionization EnergyEnergy

energy required to remove an electron from an atom; to form a cation

kJ/mol

attraction of an atom for an added electron; to form an anion

kJ/mol

Electron Electron AffinityAffinity

Atomic Atomic RadiusRadius

estimate of the size of an atomdistance between the nucleus and the likely location of electron cloud

ability of an atom to compete with other atoms for electrons shared between themi.e. who wants them more?

Electro-Electro-negativitynegativity

Across a PeriodAcross a Periodradius decreasesionization energy increaseselectronegativity increases

b/c number of protons increases, as does number

of electrons… number of valence electrons increases… so EMF increases… so valence electrons held more tightly…

Atomic RadiusAtomic Radius

1

2

3

45 6

7 8 9 10

11

1213

1415 16 17 18

19

20

0

0.5

1

1.5

2

2.5

0 2 4 6 8 10 12 14 16 18 20 22

Atomic Number

PERIOD 2

PERIOD 3

Ionization EnergyIonization Energy

1

2

3

45

6

78

9

10

11

1213

14

15 16

17

18

19

20

0

0.5

1

1.5

2

2.5

3

0 2 4 6 8 10 12 14 16 18 20 22

Atomic Number

PERIOD 2

PERIOD 3

ElectronegativityElectronegativity

1

3

4

5

6

78

9

1112

1314

1516

17

1920

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

0 2 4 6 8 10 12 14 16 18 20 22

Atomic Number

PERIOD 2

PERIOD 3

Down a FamilyDown a Familyradius increasesionization energy decreaseselectronegativity decreases

b/cnumber of energy levels increases…so valence electrons held less tightly

b/c further away from nucleus…

Atomic RadiusAtomic RadiusFamily IA

Family IIA

1

3

11

1937

55 87

4

12

20

38 5688

0

50

100

150

200

250

300

0 10 20 30 40 50 60 70 80 90 100

ATOMIC NUMBER

Ionization EnergyIonization Energy

Family IA

Family IIA

1

3 1119 37 55 87

4

12

2038

56 88

0

200

400

600

800

1000

1200

1400

0 10 20 30 40 50 60 70 80 90 100

ATOMIC NUMBER

ElectronegativityElectronegativity

Family IA

Family IIA

1

3 1119 37 55

87

4

12

20 38 56 88

0

0.5

1

1.5

2

2.5

0 10 20 30 40 50 60 70 80 90 100

ATOMIC NUMBER

Alkaline Earth Metals LabAlkaline Earth Metals LabAn element that is highly reactive tends to gain or lose electrons very easily.A precipitate is an insoluble solid formed as a result of a chemical reaction.In this lab, magnesium formed the least number of precipitates, while barium formed the greatest number of precipitates.Why do you think reactivity increases down a family???

REGIONS OF THE TABLEREGIONS OF THE TABLE

METALS

METALLOIDS

NONMETALS

One more!

MetalsMetalsFound to LEFT of zigzag line on tableGood conductors of heat & electricityMalleable (can hammer into thin sheet without breaking)

Ductile (can pull into thin wire without breaking)

High melting & boiling pointsShiny in lusterTend to lose electrons

NonmetalsNonmetalsFound to RIGHT of zigzag line on tablePoor conductors of heat & electricityBrittle when solid (break irregularly)

Dull in lusterLow melting & boiling pointsTend to gain electrons

Metalloids aka Metalloids aka Semi-MetalsSemi-Metals

Found along both sides of zigzag line, with exception of Al and PoProperties of both metals & nonmetalsOkay conductors of heat & electricityShiny or dull

Who am I?Who am I?Use the clues and a periodic table to predict the element.The number of clues is shown in the lower right corner.

1. Who am I?1. Who am I?

Very good ability to conduct electricityNever found alone in natureWhen combined with other elements, usually give up 1 valence electronOnly one letter in symbol

4 clues4 clues

2. Who am I?2. Who am I?

More valence electrons than oxygenMore protons than calciumFewer protons than krypton

3 clues3 clues

3. Who am I?3. Who am I?

Poor conductorUsually found as a gasDo not bond well with othersSometimes found in signs outside restaurants

4 clues4 clues

4. Who am I?4. Who am I?Second lowest electronegativity of periodOne of most reactive in familyNot radioactiveAdd 50 protons and I’m now another element in my family

4 clues4 clues

5. Who am I?5. Who am I?

Usually found as a gasVery reactiveLightest element in familyOften form -1 ion

4 clues4 clues

6. Who am I?6. Who am I?

RadioactiveHighest atomic radius in familyUsually form -2 ion

3 clues3 clues

7. Who am I?7. Who am I?

Never found alone or unbonded in natureMost commonly form +2 ionSecond highest number of protons in family

3 clues3 clues

8. Who am I?8. Who am I?

All other members of family are metals

• Most abundant element in universe

2 clues2 clues

9. Who am I?9. Who am I?• Metals, nonmetals, and semi-

metals all found in family• Same number of protons as the

sum of the protons in the two elements directly above

2 clues2 clues

10. Who am I?10. Who am I?

• Highest ionization energy in family• Family contains metals, nonmetals,

and semi-metals• Can form positive or negative ion

3 clues3 clues

ThatThat’’s All Folks!s All Folks!

Once you have finished, check your answers with a

peer.