A. Atomic MassA. Atomic Mass

The average atomic mass is The average atomic mass is the number at the bottom of the number at the bottom of each squareeach square

Found by averaging the Found by averaging the natural abundances of its natural abundances of its isotopesisotopes

Atomic mass = # pAtomic mass = # p++ + n+ n00

B. IsotopesB. Isotopes

Atoms of the same element with Atoms of the same element with different mass numbers.different mass numbers.

C126Mass #

Atomic #

Nuclear symbol:Nuclear symbol:

Hyphen notation: Hyphen notation: carbon-12carbon-12

B. IsotopesB. Isotopes

© Addison-Wesley Publishing Company, Inc.

B. IsotopesB. Isotopes

Chlorine-37Chlorine-37

– atomic #:atomic #:

– mass #:mass #:

– # of protons:# of protons:

– # of electrons:# of electrons:

– # of neutrons:# of neutrons:

1717

3737

1717

1717

2020

Cl3717

Ch. 3 - The Periodic Ch. 3 - The Periodic Table Table

OrganizationOrganizationMetallic CharacterMetallic CharacterRows & ColumnsRows & ColumnsTable Sections Table Sections

A. Metallic CharacterA. Metallic Character

1

2

3

4

5

6

7

MetalsMetals NonmetalsNonmetals MetalloidsMetalloids

MetalsMetals

Good Good conductorsconductors of heat and of heat and electricityelectricity

Found in Groups 1 & 2, middle of Found in Groups 1 & 2, middle of table in 3-12 and some on right side table in 3-12 and some on right side of tableof table

Have Have lusterluster, are , are ductileductile and and malleablemalleable

Alkali MetalsAlkali Metals

Group 1Group 1 Very reactiveVery reactive Form +1 ionsForm +1 ions CationsCations Examples: H, Li, NaExamples: H, Li, Na

Alkaline Earth MetalsAlkaline Earth Metals

Group 2Group 2 ReactiveReactive Form 2+ ionsForm 2+ ions CationsCations Examples: Be, Mg, Ca, etcExamples: Be, Mg, Ca, etc

Transition MetalsTransition Metals

Groups 3-12 on the Periodic TableGroups 3-12 on the Periodic Table Much less reactive than Alkali or Much less reactive than Alkali or

Alkaline Earth MetalsAlkaline Earth Metals Only 1 that is a liquid at room tempOnly 1 that is a liquid at room temp

– Mercury – HgMercury – Hg Examples: Cr, Co, Ni, Fe, Cu, Ag, AuExamples: Cr, Co, Ni, Fe, Cu, Ag, Au

NonmetalsNonmetals

Not good conductorsNot good conductors Found on right side of periodic table Found on right side of periodic table

– AND hydrogen– AND hydrogen Usually brittle solids or gasesUsually brittle solids or gases

HalogensHalogens

Group 17Group 17 Very reactiveVery reactive Form 1- ionsForm 1- ions AnionsAnions Examples: F, Cl, Br, etcExamples: F, Cl, Br, etc

Noble GasesNoble Gases

Group 18Group 18 Unreactive, inert, “noble”Unreactive, inert, “noble” Have a 0 charge, no ionsHave a 0 charge, no ions Examples: He, Ne, Ar, Kr, etcExamples: He, Ne, Ar, Kr, etc

MetalloidsMetalloids

Sometimes called semiconductorsSometimes called semiconductors Form the “stairstep” between metals Form the “stairstep” between metals

and nonmetalsand nonmetals Have properties of both metals and Have properties of both metals and

nonmetalsnonmetals Examples: B, Si, Sb, Te, As, GeExamples: B, Si, Sb, Te, As, Ge

State at Room TemperatureState at Room Temperature

Most are solidMost are solid State changes with change in State changes with change in

temperaturetemperature

B. Table SectionsB. Table Sections

1

2

3

4 5

6

7

Representative ElementsRepresentative Elements Transition MetalsTransition Metals Inner Transition MetalsInner Transition Metals

B. Table SectionsB. Table Sections

1

2

3

4

5

6

7

Lanthanides - part of period 6

Actinides - part of period 7

Overall Configuration

C. Columns & RowsC. Columns & Rows

1

2

3

4 5

6

7

Group Group (Family)(Family) PeriodPeriod

Ch. 3 - The Periodic Ch. 3 - The Periodic Table Table

Periodic TrendsPeriodic TrendsTermsTerms

Periodic Trends Periodic Trends

Dot DiagramsDot Diagrams

Periodic LawPeriodic Law

– Properties of elements repeat Properties of elements repeat

periodically when the elements are periodically when the elements are

arranged by increasing atomic number.arranged by increasing atomic number.

A. TermsA. Terms

A. TermsA. Terms

Valence ElectronsValence Electrons– ee-- in the outermost energy level in the outermost energy level

Atomic RadiusAtomic Radius

– Measure of the size of an atomMeasure of the size of an atom

B. Periodic TrendsB. Periodic Trends

Group # = # of valence eGroup # = # of valence e -- (except He) (except He)– Families have similar reactivity.Families have similar reactivity.

Period # = # of energy levelsPeriod # = # of energy levels

1A

2A 3A 4A 5A 6A 7A

8A

C. Lewis DiagramsC. Lewis Diagrams

Dots represent the valence eDots represent the valence e--

EXEX: Sodium: Sodium EXEX: Chlorine: Chlorine