The Periodic TableThe Periodic Table

What Does Periodic Mean?What Does Periodic Mean?

Periodic means repeated in a patternPeriodic means repeated in a patternThink about a calendar:Think about a calendar:Weeks are periodic – they repeat Weeks are periodic – they repeat

every 7 daysevery 7 days

Dimitri Mendeleev (1834 - 1907)Dimitri Mendeleev (1834 - 1907)

Created the first way Created the first way to organize all known to organize all known elementselements

Based his table on Based his table on the pattern of the pattern of chemical propertieschemical properties

Mendeleev’s Periodic TableMendeleev’s Periodic Table

Based on Based on chemical chemical propertiesproperties

Organized Organized by atomic by atomic massesmasses

Predicted Predicted unknown unknown elementselements

Henry Moseley (1887 – 1915)Henry Moseley (1887 – 1915)

His work led to a His work led to a reorganization of reorganization of Mendeleev’s Mendeleev’s table by atomic table by atomic numbernumber

Killed by a sniper Killed by a sniper in World War in World War One at age 27One at age 27

The Modern Periodic TableThe Modern Periodic Table

Organized Organized intointo

Rows = Rows = PeriodsPeriods

Columns = Columns = FamiliesFamilies

Periods and FamiliesPeriods and Families

The families are numbered at the top The families are numbered at the top of your periodic table in your reference of your periodic table in your reference tabletable

Take a pen and number the periodsTake a pen and number the periodsNumber one is the row with Number one is the row with

HydrogenHydrogenNumber seven is the row with Number seven is the row with

FranciumFrancium

Names of FamiliesNames of Families

Group Group

1A or 11A or 1

Alkali Alkali MetalsMetals

Names of FamiliesNames of Families

Group Group

2A or 22A or 2

Alkaline Alkaline Earth Earth MetalsMetals

Names of FamiliesNames of Families

Group Group

7A or 177A or 17

HalogensHalogens

Names of FamiliesNames of Families

Group Group

8A or 188A or 18

Noble Noble GassesGasses

Special GroupsSpecial Groups

Groups Groups

3-123-12

Transition Transition MetalsMetals

Special GroupsSpecial Groups

11stst Row at Row at BottomBottom

LanthanoidsLanthanoids

OROR

LanthanidesLanthanides

Special GroupsSpecial Groups

22ndnd Row at Row at BottomBottom

ActinoidsActinoids

OROR

ActinidesActinides

One Other FeatureOne Other Feature

Notice the Notice the dark dark stairstep stairstep line.line.

Separates Separates metals metals from from nonmetalsnonmetals

MetalsMetals

To the left of the stair-step lineTo the left of the stair-step lineTypically solids with high melting Typically solids with high melting

pointspointsGood conductors of heat and Good conductors of heat and

electricityelectricityMalleableMalleable – can be formed into a – can be formed into a

different shapedifferent shapeDuctileDuctile – can be drawn into wires – can be drawn into wires

MetalsMetals

As you move left across the periodic As you move left across the periodic table, metals become more reactivetable, metals become more reactive

As you move down a group (family), As you move down a group (family), metals become more reactivemetals become more reactive

Remember the video about cesium?Remember the video about cesium?Where are the most reactive Where are the most reactive

elements on the periodic table?elements on the periodic table?

MetalloidsMetalloids

Touching the stair-step line Touching the stair-step line Have properties in between metals Have properties in between metals

and nonmetalsand nonmetalsSemiconductors – Think silicon in Semiconductors – Think silicon in

computer chipscomputer chips

NonmetalsNonmetals

To the right of the stair-step lineTo the right of the stair-step lineTypically gasses with low melting Typically gasses with low melting

pointspointsVery poor conductors of heat and Very poor conductors of heat and

electricityelectricityBrittle – break rather than change Brittle – break rather than change

shapeshape

NonmetalsNonmetals

As you move right across the periodic As you move right across the periodic table, nonmetals become more table, nonmetals become more reactivereactive

As you move down a group (family), As you move down a group (family), nonmetals become less reactivenonmetals become less reactive

Where are the most reactive Where are the most reactive nonmetals?nonmetals?

Exit TicketExit Ticket

On the index card, please answer On the index card, please answer the following questions:the following questions:

1.1. Which group is the halogens?Which group is the halogens?

2.2. What is the most reactive non-What is the most reactive non-metal?metal?

3.3. What is the most reactive metal?What is the most reactive metal?

4.4. List two metalloids.List two metalloids.