Chapter 5Chapter 5

The Periodic Table

Dimitri MendeleevDimitri Mendeleev

Mendeleev’s ProposalMendeleev’s Proposal

Arranged the elements into rows in order of increasing mass.

Elements with similar properties were in the same column.

Mendeleev ‘s PredictionsMendeleev ‘s Predictions

Mendeleev predicted where new elements would appear in the table.

Properties of new elements showed how useful his periodic table could be.

Homework Homework

5-1 WorksheetDue: 11/5/08

Periodic TablePeriodic Table

Arrangement of the elements:

Chemical Properties

Atomic Number Number of Protons

GroupGroup

Repeating Chemical Properties

Vertical Column

Increase Mass

Group 11-1BGroup 11-1B

GroupsGroups

Same number of

Valence Electrons

(Number of Electrons in the Outer Energy Level!!)

Group 2Group 2

Be MgCa

SrBa

Ra

PeriodsPeriods

Horizontal Rows

Same Number of

Energy Levels

Period - 2Period - 2

Li Be B C

N O F Ne

H - HydrogenH - HydrogenC - CarbonC - CarbonO - OxygenO - OxygenFe - Iron (ferrum)Fe - Iron (ferrum)He - HeliumHe - HeliumCu - Copper (cuprum)Cu - Copper (cuprum)Hg - Mercury (hydragyrum)Hg - Mercury (hydragyrum)Co - Cobalt Co - Cobalt Unp - UnnilpentiumUnp - Unnilpentium

Names and Chemical Symbols

Same group - Same number of electrons in their outer shells.

Group 1 (H) – 1e-Group 2 (Be) – 2e-Group 13 (B) – 3e-Group 14 (C) – 4e-Group 15 (N) – 5e-Group 16 (O) – 6e-Group 17 (F) – 7e-Group 18 (He) – 8e-

15

30.96376Phosphorus

PAtomic Number(# of Protons)

Symbol

AverageAtomic Mass

(31)

Name

Atomic Mass UnitAtomic Mass Unit

Atomic mass unit is equal to one-twelfth of the mass

of the nucleus of a carbon-12 atom.

Atomic Mass UnitAtomic Mass Unit

Atomic Mass UnitAtomic Mass Unit

p+

n0

Proton: Atomic Mass – 1amu

Neutron: Atomic Mass – 1amu

Atomic Mass of 7 amuAtomic Mass of 7 amu

IsotopesIsotopes

Atoms of the same element can have different

numbers of neutrons.

Isotopes of ChlorineIsotopes of Chlorine

Cl17

35

17 Proton18 Neutrons

17 Proton20 Neutrons

76%

Cl17

3724%

Average Weighted MassAverage Weighted Mass of of

Chlorine Chlorine

35.453amu

Metals

Non-Metals

Metalloids

MetalsMetals

75% of the

Elements!!!

MetalsMetals

Physical Properties of Metals:

1. Metallic shine or luster.

2. Usually solids at room temperature.

MetalsMetals

3. Malleable

(Hammered, pounded, or pressed into different shapes

without breaking.)

MetalsMetals

4. Ductile:

(Drawn into thin sheets or

wires without breaking.)

5. Good conductors of heat and electricity.

MetalsMetals

Metals tend to give up e-.

Na

Most Reactive MetalsMost Reactive Metals

FranciumMost Active Metal

FrLi

Non-MetalsNon-Metals

There are 17 nonmetals.They have four major

physical properties.

Non-MetalsNon-Metals

Physical Properties

1. Rarely have metallic luster.

2. Usually gases at room temperature.

Non-MetalsNon-Metals

3. Nonmetallic solids are neither malleable nor ductile.

4. Poor conductors of heat and electricity.

Non-Metals tend to gain e-.

Non-MetalsNon-Metals

Cl

Most Reactive Non-MetalMost Reactive Non-Metal

FI

Fluorine

Most Active

Non-Metal

Met

allo

ids

Met

allo

ids

The seven metalloids are: BSiGeAsSbTePo

B

Si

Ge As

Sb Te

Po

Metalloid PropertiesMetalloid Properties

Characteristics in between that of the metals and the nonmetals.

Sometimes they are good conductors of heat and electricity.

Variations across a PeriodVariations across a Period

Across a PeriodLess Metallic more Non-Metallic

Homework Homework

5-2 WorksheetDue: 11/13/08

Valence ElectronsValence Electrons

The electrons in the highest occupied energy

level of an atom.

Valence ElectronsValence Electrons

Elements in a group have similar properties because

they have the same number of valence

electrons..

Alk

ali M

etal

sA

lkal

ine

Ear

th M

etal

s

Nob

le G

ases

Hal

ogen

sO

xyge

n

Nit

roge

n

Car

bon

Bor

on

Alkali MetalAlkali Metal Group 1A Very reactive metals. Do not occur freely in nature. Only one electron in their

outer shell. (1 valence Electron)

Li

Na

K

Rb

Cs

Fr Most reactive metal!!!!Most reactive metal!!!!

Alkaline Earth MetalAlkaline Earth Metal Group 2A Very reactive Not found free in nature. Two electron in their outer shell.

(2 Valence Electron)Magnesium and Calcium

important elements in life.

Mg

Ca

Sr

Ba

Ra

Be

Boron Family Boron Family Group 3A Three electrons in their outer

shell.

(3 Valence Electrons)Aluminum is the most abundant

metal in the Earth’s crust.

Al

Ga

In

Tl

B

Carbon Family Carbon Family Group 4A.Four electrons in their outer shell.

(4 Valence Electrons) Consists of:

One nonmetal (carbon) Two metals (tin and lead) Two metalloids (silicon and germanium).

Except for water, most compounds in your body contain carbon.

Si

Ge

Sn

Pb

C

Nitrogen Family Nitrogen Family

Group 5A.Five electrons in the outermost

energy level.

(5 Valence Electrons)They physical and chemical

properties that are strikingly different.

N and P make up fertilizer.

P

As

Sb

Bi

N

Oxygen Family Oxygen Family Group 6A.Six electrons in their outermost

energy level.

(6 Valence Electrons)Oxygen is the most abundant

element in the earth’s crust.

S

Se

Te

Po

O

Halogens Halogens

The halogens are five non-metallic elements found in group 7A of the periodic table.

All halogens have 7 electrons in their outer shells.

The halogens exist, at room temperature, in all three states of matter.

Cl

Br

I

At

F

Noble Gases Noble Gases The six noble gases are found in

group 8A of the periodic table. These elements were considered to

be inert gases. All noble gases have the maximum

number of electrons possible in their outer shell (2 for Helium, 8 for all others), making them stable.

Colorless/Odorless Gases

Ne

Ar

Kr

Xe

Rn

He

Electron Dot DiagramElectron Dot DiagramLewis DiagramLewis Diagram

Dot Diagram:• Symbol of the element • Dots for Valence Electrons. (Outer most energy level Electrons)

C Cl Ne Na

HomeworkHomework

5-3: WorksheetDue: 11/14/08

Word-Wise & Math Due: 11/17/08

Test: 11/19/08

Test 11/20/07