The Periodic TableThe Periodic Table

Introduction

Mendeleev’s Periodic TableMendeleev’s Periodic Table

Dmitri Mendeleev

Mendeleev’s TableMendeleev’s Table Grouped elements in columns by similar Grouped elements in columns by similar

properties in order of increasing atomic properties in order of increasing atomic mass.mass.

Found some inconsistencies - felt that the Found some inconsistencies - felt that the properties were more important than the properties were more important than the mass, so switched order.mass, so switched order.

Found some gaps.Found some gaps. Must be undiscovered elements.Must be undiscovered elements. Predicted their properties before they were Predicted their properties before they were

found.found.

Modern Russian TableModern Russian Table

Chinese Periodic TableChinese Periodic Table

A Spiral Periodic A Spiral Periodic TableTable

““Mayan” Mayan”

Periodic Periodic TableTable

The modern tableThe modern table

Elements are still grouped by properties.Elements are still grouped by properties. Similar properties are in the same column.Similar properties are in the same column. Order is in increasing atomic number.Order is in increasing atomic number. Added a column of elements Mendeleev Added a column of elements Mendeleev

didn’t know about.didn’t know about. The noble gases weren’t found because The noble gases weren’t found because

they didn’t react with anything.they didn’t react with anything.

Orbital filling tableOrbital filling table

Group 1: Alkali MetalsGroup 1: Alkali Metals

Most active metals, only found in compounds in Most active metals, only found in compounds in naturenature

React violently with water to form hydrogen gas and React violently with water to form hydrogen gas and a strong base: 2 Na (s) + Ha strong base: 2 Na (s) + H22O (l) O (l) 2 NaOH (aq) + 2 NaOH (aq) +

HH22 (g) (g)

1 valence electron1 valence electron Form +1 ion by losing that valence electronForm +1 ion by losing that valence electron Form oxides like NaForm oxides like Na22O, LiO, Li22O, KO, K22OO

Group 2: Alkaline Earth Group 2: Alkaline Earth MetalsMetals

Very active metals, only found in compounds Very active metals, only found in compounds in naturein nature

React strongly with water to form hydrogen React strongly with water to form hydrogen gas and a base: gas and a base: Ca (s) + 2 HCa (s) + 2 H22O (l) O (l) Ca(OH) Ca(OH)22 (aq) + H (aq) + H22 (g) (g)

2 valence electrons2 valence electrons Form +2 ion by losing those valence electronsForm +2 ion by losing those valence electrons Form oxides like CaO, MgO, BaOForm oxides like CaO, MgO, BaO

Groups 3-11: Transition Groups 3-11: Transition MetalsMetals Many can form different possible charges of ionsMany can form different possible charges of ions If there is more than one ion listed, give the charge If there is more than one ion listed, give the charge

as a Roman numeral after the nameas a Roman numeral after the name CuCu+1+1 = copper (I) Cu = copper (I) Cu+2+2 = copper (II) = copper (II) Compounds and solutions containing these metals Compounds and solutions containing these metals

can be colored.can be colored.

Group 17: HalogensGroup 17: Halogens

Most reactive nonmetalsMost reactive nonmetals React violently with metal atoms to form React violently with metal atoms to form

halide compounds: 2 Na + Clhalide compounds: 2 Na + Cl22 2 NaCl 2 NaCl

Only found in compounds in natureOnly found in compounds in nature Have 7 valence electronsHave 7 valence electrons Gain 1 valence electron from a metal to form Gain 1 valence electron from a metal to form

-1 ions-1 ions Share 1 valence electron with another Share 1 valence electron with another

nonmetal atom to form one covalent bond.nonmetal atom to form one covalent bond.

Group 18: Noble GasesGroup 18: Noble Gases

Are completely nonreactive since they have Are completely nonreactive since they have eight valence electrons, making a stable octet.eight valence electrons, making a stable octet.

Kr and Xe can be forced, in the laboratory, to Kr and Xe can be forced, in the laboratory, to give up some valence electrons to react with give up some valence electrons to react with fluorine.fluorine.

Since noble gases do not naturally bond to any Since noble gases do not naturally bond to any other elements, one atom of noble gas is other elements, one atom of noble gas is considered to be a molecule of noble gas. This considered to be a molecule of noble gas. This is called ais called a monatomic monatomic molecule. Ne represents molecule. Ne represents an atom of Ne and a molecule of Ne.an atom of Ne and a molecule of Ne.

Properties of MetalsProperties of Metals Metals are good conductors of heat and electricity

Metals are malleable

Metals are ductile

Metals have high tensile strength

Metals have luster

Properties of MetalsProperties of Metals Lose electrons easilyLose electrons easily Low ionization energy and Low ionization energy and

electronegativity. electronegativity. Form positive ions when combining with Form positive ions when combining with

other atoms by losing electrons.other atoms by losing electrons. Elements with the most metallic Elements with the most metallic

properties are in the lower left of the properties are in the lower left of the periodic table. periodic table.

Examples of MetalsExamples of Metals

Potassium, K reacts with water and must be stored in kerosene

Zinc, Zn, is more stable than potassium

Copper, Cu, is a relatively soft metal, and a very good electrical conductor.

Mercury, Hg, is the only metal that exists as a liquid at room temperature

Properties of Properties of NonmetalsNonmetals

Carbon, the graphite in “pencil lead” is a great example of a nonmetallic element. Nonmetals are poor conductors of heat and electricity Nonmetals tend to be brittle Many nonmetals are gases at room temperature

NonmetalsNonmetals Gain electrons easily.Gain electrons easily. High ionization energies and High ionization energies and

electronegativities.electronegativities. Form negative ions when combining with Form negative ions when combining with

metal atoms by gaining electrons.metal atoms by gaining electrons. Produce covalent bonds by sharing electrons Produce covalent bonds by sharing electrons

with other nonmetals. with other nonmetals. Exist as gases, molecular solids, or network Exist as gases, molecular solids, or network

solids at room temp. (Bromine exception).solids at room temp. (Bromine exception).

Nonmetals Con’tNonmetals Con’t Do not/are not have luster, good Do not/are not have luster, good

conductors, ductile. conductors, ductile. Many are diatomic molecules (BrMany are diatomic molecules (Br22, I, I22, ,

NN22, Cl, Cl22, H, H22, O, O22, F, F22).).

Elements with nonmetallic properties Elements with nonmetallic properties appear in the upper right of the periodic appear in the upper right of the periodic table. table.

Examples of NonmetalsExamples of Nonmetals

Sulfur, S, was once known as “brimstone”

Microspheres of phosphorus, P, a reactive nonmetal

Graphite is not the only pure form of carbon, C. Diamond is also carbon; the color comes from impurities caught within the crystal structure

Metals & NonmetalsMetals & Nonmetals

Properties of Properties of MetalloidsMetalloids

Metalloids straddle the border between metals and nonmetals on the periodic table.

They have properties of both metals and nonmetals. Metalloids are more brittle than metals, less brittle than most nonmetallic solids Metalloids are semiconductors of electricity Some metalloids possess metallic luster

KNOW THESE!

Silicon, Si – A MetalloidSilicon, Si – A Metalloid Silicon has metallic luster Silicon is brittle like a nonmetal Silicon is a semiconductor of electricity

Other metalloids include:

Boron, B Germanium, Ge Arsenic, As Antimony, Sb Tellurium, Te

MetalloidsMetalloids

Half of the distance between nucli in covalently bonded diatomic molecule

"covalent atomic radii"

Periodic Trends in Atomic Radius   Radius decreases across a period

Increased nuclear charge, more protons; electronsdo not get further from nucleus.

  Radius increases down a group Addition of principal energy levels

Determination of Atomic Radius:Determination of Atomic Radius:

Table of Table of Atomic Atomic RadiiRadii

Ionic RadiiIonic RadiiCations

  Positively charged ions   Smaller than the

corresponding atomAnions

  Negatively charged ions   Larger than the corresponding atom

Table of Ion SizesTable of Ion Sizes

Ionization EnergyIonization Energy

The energy required to remove the most loosely held The energy required to remove the most loosely held valence electron from an atom in the gas phase.valence electron from an atom in the gas phase.

High electronegativity means high ionization energy High electronegativity means high ionization energy because if an atom is more attracted to electrons, it because if an atom is more attracted to electrons, it will take more energy to remove those electrons.will take more energy to remove those electrons.

Metals have low ionization energy. They lose Metals have low ionization energy. They lose electrons easily to form (+) charged ions.electrons easily to form (+) charged ions.

Nonmetals have high ionization energy but high Nonmetals have high ionization energy but high electronegativity. They gain electrons easily to form electronegativity. They gain electrons easily to form (-) charged ions when reacted with metals, or share (-) charged ions when reacted with metals, or share unpaired valence electrons with other nonmetal unpaired valence electrons with other nonmetal atoms.atoms.

Another Way to Look at Another Way to Look at Ionization EnergyIonization Energy

ElectronegativityElectronegativity

A measure of the ability of an atom in a chemical compound to attract electrons

  Electronegativities tend to increase across a periodWhy:

  Electronegativities tend to decrease down a group or remain the sameWhy: Electrons farther from the nucleus experience less nuclear attraction

Periodic Table of Periodic Table of ElectronegativitiesElectronegativities

Summation of Periodic TrendsSummation of Periodic Trends