The Periodic Table Basics & Naming & Formulas of Compounds

Chemistry-CPPeriods 7

J.W. Dobereiner In 1860, there were only 63 elements

known Classified some elements into triads--

groups of three Triads had: Similar chemical properties &

physical properties that varied in an orderly way

Important because: He grouped elements with similar properties revealing an orderly pattern in the elements’ properties.

Examples of Triads

Halogen Triad: Chlorine, Bromine and Iodine

Coinage Triad: Copper, Silver & Gold

Metal Triad: Calcium, Strontium & Barium

J.A.R. Newlands (1865)

Realized that when the elements were arranged by increasing atomic mass, the properties of the 8th element were similar to the 1st element.

Law of Octaves: The periodic pattern repeats itself every 8 elements

Dmitri Mendeleev Russian chemist who developed

the first periodic table Listed the elements according to

atomic mass Important because: He showed

the properties of the elements repeat in an orderly way from row to row of the table

Periodic: the tendency to recur at regular intervals or repeating in a pattern

Things that are periodic:

Mendeleev’s periodic table was so successful because it allowed him to predict the properties of still unknown elements

Eka-Aluminum (Gallium) Eka-Silicon (Germanium)

Lothar Meyer (1869)

Published almost the same element classification scheme as Mendeleev but did not receive credit because Mendeleev revealed his first and Mendeleev was more successful at demonstrating its usefulness

Henry Moseley Realized that the periodic table was not in

the perfect order Arranged the modern periodic table. Listed the elements according to atomic

number Important because: once arranged by

atomic number all the elements were in order by their chemical & physical properties

The modern periodic table is listed in order of atomic number

Periodic Law

The physical and chemical properties of the elements repeat in a regular pattern when they are arranged in order of increasing atomic number

Periodic Table

Arrangement of the elements in order of their atomic numbers so that the elements are periodic functions of their atomic numbers.

Element Key: •Includes the element symbol, element name, atomic mass and atomic number

•May include other information

Groups (also called Families)

The vertical columns on the periodic table There are 18 groups, labeled with the numbers

1-18.1

2

3 4

15

5 76 98

17 16

18

1413

1211 10

Group NamesAlkal i

Metals

Alkal ine

Earth

Met.

Transition Metals

Boron

Group

Carbon

Group

Nitrogen

Group

Oxygen

Group

Halogens

Noble

Gases

Lanthanides

Actinides

Periods Horizontal Rows on the Periodic Table There are 7 periods labeled with the numbers

1-7.

1

2

3

4

5

6

7

Examples

States of Matter (at Room Temp.)Solids: Black lettering on the wall periodic table

Liquids: Blue lettering on the wall periodic table (Hg & Br)

Gases: Red lettering on the wall periodic table (noble gases, F, Cl, O, N, H)

METALSLeft of the zig-zag lineException: Hydrogen

PROPERTIES OF METALS Typically solids at room temperature Good conductors of heat & electricity High melting points Luster (shiny) Malleable (can be hammered into

sheets) Ductile (can be pulled into wires)

Nonmetals-Located right of the zig-zag line

Exception: hydrogen

Nonmetals

Make up 99% of Earth’s atmosphere (Oxygen & Nitrogen)

Do not conduct electricity and poor conductors of heat

Brittle when solids Many are gases at room temperature Lack luster Low melting points

MetalloidsElements bordered by the zig-zag line (exception: Al is a metal)

Metalloids

Properties of the Metalloids Have some chemical and physical

properties of metals and other properties of nonmetals

Some are semiconductors Semiconductor: An element that does not

conduct electricity as well as a metal but does conduct slightly better than a nonmetal

Computers, Handheld electronic devices, calculators

Radioactive Elements Elements with atomic numbers higher

than 82 Radioactivity: Spontaneous emission of

radiation Elements are radioactive because

they have too many or too few neutrons The protons in the nucleus naturally repel

each other. The neutrons are the “glue” that hold the nucleus together.

Synthetic Elements

The synthetic elements are the elements with the outlined symbols.

Synthetic elements are not found in nature. They are man-made elements.

Atomic Model Diagram

ENERGY LEVELS

Electrons with the most energy are located farthest from the nucleus

Electrons with the lowest

energies are located close

to the nucleus.

ENERGY lEVELS

Energy level 3 contains a maximum

of 18 electrons

Level 1 contains a

maximum of 2 electrons

Level 2 contains a

maximum of 8 electrons

The 4th energy level contains a maximum

of 32 electrons

EXAMPLES

Draw an atomic diagram of:

Hydrogen Neon Magnesium

Carbon Lithium Sodium

Atomic Model Diagram

Valence Electrons The # of electrons in the highest (outermost) energy

level

Transition Metals: The # of valence electrons for a transition metal can vary due to the closeness of their s & d sublevels

Exceptions: Silver is always 1 valence electron Zinc is always 2 valence electrons

Inner Transition Metals: Typically have 3 valence electrons

Group 1 2 13 14 15 16 17 18

Lewis Dot Diagrams The element symbol, used to represent the

element’s inner level electrons, is surrounded by dots to represent the element’s valence electrons

The # of dots must equal the # of valence electrons, no more than 2 dots per side

Remember: The valence electrons can never be greater than 8, therefore, there can never be more than 8 dots.

Oxidation Number The charge an atom acquires when

it gains or loses electrons to become stable Ion: Atom that has a charge due to

the loss or gain of electrons Octet Rule: Atoms tend to gain, lose

or share electrons so that each atom has a full outermost energy level which is typically 8 valence electrons (octet)

ION

• An atom becomes an ion when it gains or loses electrons–The protons in an atom never change—an atom CANNOT gain or lose protons

An ion does not have equal numbers ofprotons and electrons (the positive

does not = the negative)…therefore…

an ION is a CHARGED atom

ION

ATOM ION

Oxidation Number

If an element loses electrons, its oxidation # is a _______________ number because: there are more positive protons than negative electrons

Ca+ion (a positively charged ion)

Elements with 1-3 valence electrons: Lose electrons to become stable Form ions with a positive charge

ATOM vs. CATION

Positively charged proton

Negatively charged electron

If an element gains electrons, its oxidation # is a _______________ number because: there are more negative electrons than positive protons.

A n ion Elements with 5-7 valence electrons:

Gain electrons to become stable Form ions with a negative charge

Elements with 4 valence electrons: Metals will lose electrons, becoming positive ions Nonmetals will gain electrons, becoming negative ions

Oxidation Number

egative

ATOM vs. ANION

Positively charged proton

Negatively charged electron

Oxidation Number

Group # 1 2 13 14 15 16 17 18

Na Mg Al Si P S Cl Ar

Transition Metals Oxidation #s may vary Except: Ag+1 & Zn+2

Inner Transition Metals: Typically a +3 Oxidation Number

Oxidation Number

Examples

CA+IONS To Name a Cation: Name the Metal

Transition Metals: Name the Metal followed by a Roman Numeral in Parentheses to Indicate the Metal’s charge Remember: The oxidation number can change for

transition metals, so it is important to indicate the metal’s charge

Exceptions: Zinc is always +2 and Silver is always +1 so they are

transition metals that do not require Roman Numerals

ROMAN NUMERALS1 I 6 VI

2 II 7 VII

3 III 8 VIII

4 IV 9 IX

5 V 10 X

ANIONS To Name: Change the ending of the

nonmetal’s name to –ide.

Examples: Sulfide, Iodide, Selenide

ION SYMBOL ElementSymbolOxidation#

The oxidation # is the charge the atom acquires when it gains or loses electrons to become stable (acquire 8 electrons)

Group #

1 2 13 14 15 16 17 18

OXIDATION NUMBERS ARE PERIODIC

EXAMPLES Write the ion symbol for the ions formed from

the following elements.

a) Lithium b) Aluminum

c) Silver d) Phosphorus

e) Selenium f) Bromine

MORE EXAMPLES Name the following ions

a) Fe2+ b) Cl-

c) N3- d) K+

e) Zn2+ f) P3-

POLYATOMIC IONS Common Polyatomic Ions—This table is on your periodic tables

+1-1 -2 -3

Ammonium, NH4

+

Acetate, C2H3O2-

Bromate, BrO3-

Chlorate, ClO3-

Chlorite, ClO2-

Cyanide, CN-

Bicarbonate, HCO3-

Hydroxide, OH-

Hypochlorite, ClO-

Iodate, IO3-

Nitrate, NO3-

Nitrite, NO2-

Permanganate, MnO4

-

Perchlorate, ClO4-

Thiocyanate, SCN-

Carbonate, CO32-

Chromate, CrO42-

Dichromate, Cr2O7

2-

Oxalate, C2O42-

Peroxide, O22-

Sulfate, SO42-

Sulfite, SO32-

Phosphate, PO43-

Phosphite, PO33-

Arsenate, AsO43-

Polyatomic Ions Names typically end in:

The only positively charged ion is:

Where should you look to find the polyatomic ions?

-ate or -ite

Ammonium (NH4+)

Polyatomic Ion Chart on your Periodic Table

What do opposites do?

A metal & a nonmetal in the same container both become stable by gaining/losing electrons---what charges will the ions in the container have?

What will those charges want to do?

ATTRACT

Metal = + Nonmetal = -

ATTRACT—Come together in an ionic bond

IONIC COMPOUNDS An ionic bond is formed between an

_______________ and a ______________ because: Opposite charges attract forming a bond Therefore, ionic bonds form between

__________________ and ________________ because: ____________form ions with positive charge and _________________ form ions with negative charge

IONIC COMPOUNDS Electrons are _______________________ in an

ionic bond because: one atom is trying to lose electrons to become stable and the other atom is trying to gain electrons to become stable

EMPIRICAL FORMULA Chemical formula for an ionic compound Lowest whole number ratio of ions in an ionic

compound

EMPIRICAL FORMULA

Al2O3Subscript: # written to the lower right of a chemical symbol that shows the number of atoms of that element present in the compound

3 WAYS TO DETERMINE AN EMPIRICAL FORMULA

1. Use Lewis Dot Diagrams

2. Use charges

3. Use the Crisscross Method

Draw the Lewis Dot Diagram for each element

Determine the number of each element necessary to make each atom

1DETERMINING THE EMPIRICAL FORMULA BY USING

LEWIS DOT DIAGRAMS TO ILLUSTRATE THE IONIC BOND

The overall charge of an ionic compound is 0 Determine the number of each ion necessary

so that the sum of the charges is 0.

2DETERMINING THE EMPIRICAL FORMULA BY USING

THE OXIDATION NUMBERS (CHARGES) OF THE IONS

Write the symbol of charge of each ion in the compound

Crisscross each ions numerical charge down to the subscript of the other ion

3DETERMINING THE EMPIRICAL FORMULA BY USING

THE CRISSCROSS METHOD

Sr3N2

Sr+2 N3-

To Name an Ionic CompoundTo Name an Ionic Compound CaCl2 Fe2O3 NaOH

Name the metal

If the metal is a transition metal, add a Roman numeral in parentheses to indicate it’s charge

Name the nonmetal, changing its suffix to –ide, or name the polyatomic ion.

EXAMPLESTo Name an Ionic Compound MgS CaSO4

Cu(C2H3O2)2

Name the metal (or the polyatomic ion if it is ammonium).If the metal is a transition metal, add a Roman numeral in parentheses to indicate it’s charge

Name the nonmetal, changing its suffix to –ide, or the polyatomic ion (if it’s more than 2 elements).

ExamplesWrite the chemical formulas for:

Cobalt(II) chloride

Potassium bromide

Manganese(IV) oxide

IONIC VS. COVALENT BONDING

IONIC COVALENT

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Covalent (Molecular) Compounds Compounds formed from covalent bonds

Covalent Bonds: Bonds formed when atoms share electrons Covalent bonds are formed between 2 or more _________.

Ionic Compounds are formed between a _________ & _________.

Which type of bond would form between the following elements?MgCl2 HI AlN

CO2 F2 SnO2

Covalent Compound Electrons are ______________ in covalent bonds.

Electrons are _________________ in ionic bonds.

Molecule A group of atoms united by covalent bonds

Polyatomic Ions are molecules that have charge!

DIATOMIC MOLECULES: Some elements only exist in nature as molecules consisting of 2 atoms of that element.

•Why? More stable as a pair!

•The 7 diatomic elements are: HONClBrIF

Molecular Substance Substance made of molecules

Molecular Formula Tells how many atoms of an element are in a single molecule of a

compound The chemical formula of a covalent compound is not the lowest whole

number ratio Different from an EMPIRICAL FORMULA which gives the lowest whole

number ratio of ions in an IONIC COMPOUND

To Name a Molecular Compound Name the 1st element. If there is more than

one of that element, use the appropriate prefix (mono- is not used on the first element)

Name the last element using the appropriate prefix and changing its ending to –ide. Since there are no metals in molecular

compounds, no Roman numerals are used.

NUMERICAL PREFIXESNUMERICAL PREFIXES11 Mono-Mono-

22 Di-Di-

33 Tri-Tri-

44 Tetra-Tetra-

55 Penta-Penta-

66 Hexa-Hexa-

77 Hepta-Hepta-

88 Octa-Octa-

99 Nona-Nona-

1010 Deca-Deca-

ExamplesExamples

NN22OO44

PClPCl55

NONO22

Dinitrogen tetroxide

Phosphorous pentachloride

Nitrogen dioxide

Chemical Formulas for Chemical Formulas for Molecular CompoundsMolecular Compounds Use the prefixes to determine the Use the prefixes to determine the

chemical formulachemical formula– Since molecular compounds do not Since molecular compounds do not

involve the transfer of electrons, involve the transfer of electrons, there are no ions—do not get there are no ions—do not get charges and no crisscrossing!charges and no crisscrossing!

ExamplesExamples

Nitrogen trifluorideNitrogen trifluoride

Diphosphorus pentoxideDiphosphorus pentoxide

Carbon tetrachlorideCarbon tetrachloride

NF3

P2O5

CCl4

•An ionic compound that contains water

within its crystal structure

•Hydrates contain water molecules that are either bound to a metal center or crystallized with the metal complex.

•The water may be evaporated off

HYDRATESHYDRATES

Uses of Hydrates

•Hydrates replace the skin's moisture and repair tissue damaged by cold and dryness.

•Desalination of Water

•Methane Hydrates

HYDRATESHYDRATESTo Identify a hydrateTo Identify a hydrate

BaClBaCl22 3H 3H22OO barium chloride trihydratebarium chloride trihydrate

To Name a hydrateTo Name a hydrate Name the ionic compound followed by the word hydrate Name the ionic compound followed by the word hydrate

with a prefix to indicate the # of water molecules attached.with a prefix to indicate the # of water molecules attached.– MgSOMgSO44 2H 2H22OO

To Write the Formula for a HydrateTo Write the Formula for a Hydrate Use the crisscross method to determine the formula of the Use the crisscross method to determine the formula of the

ionic compound, followed by a dot, followed by the # of ionic compound, followed by a dot, followed by the # of water molecules indicated by the prefix.water molecules indicated by the prefix.– Copper(II) chloride pentahydrateCopper(II) chloride pentahydrate

AcidsAcids A molecular substance that A molecular substance that

dissolves in water to produce dissolves in water to produce HH++ ions ions

The chemical formula starts The chemical formula starts with H (we will assume all are with H (we will assume all are dissolved in water)dissolved in water)

To Name a Binary AcidTo Name a Binary Acid ““Hydro”-root name of anion-“ic Acid”Hydro”-root name of anion-“ic Acid”

– Ex: Hydrobromic AcidEx: Hydrobromic Acid

To Name an Acid To Name an Acid containing a Polyatomic containing a Polyatomic IonIon Root name of Polyatomic Ion- “ic” AcidRoot name of Polyatomic Ion- “ic” Acid

– Ex: Sulfuric AcidEx: Sulfuric Acid

To determine the formula To determine the formula of an acidof an acid

Consider Hydrogen an Ion: HConsider Hydrogen an Ion: H++

Determine the charge of the Determine the charge of the anionanion

Crisscross chargesCrisscross charges

– HH++ S S2-2- HH22SS

Name the Name the following:following:

MgMgII22 hydroiodic acidhydroiodic acidNN22 dinitrogen monoxidedinitrogen monoxideCaClCaCl22●2H●2H22OO magnesium carbonatemagnesium carbonateNONO22 disulfur hexaoxidedisulfur hexaoxideNaClONaClO manganese (IV) oxidemanganese (IV) oxideHH22SS copper(II) chloride monohydratecopper(II) chloride monohydrate

More Review: Once you have these correct & checked go to More Review: Once you have these correct & checked go to

http://www.proprofs.com/quiz-school/story.php?title=chemical-naming-http://www.proprofs.com/quiz-school/story.php?title=chemical-naming-formulasformulas

And take the on-line quiz. Password is ‘chemistry’.And take the on-line quiz. Password is ‘chemistry’.

Write the Write the chemical chemical formula for:formula for:

AnswersAnswers

Copper(II) iodideCopper(II) iodide HIHI

NitrogenNitrogen NN22OO

Calcium chloride dihydrateCalcium chloride dihydrate MgCOMgCO33

Carbon tetrahydrideCarbon tetrahydride SS22OO66

Sodium hypochloriteSodium hypochlorite MnOMnO22

Sulfuric acidSulfuric acid CuClCuCl22●H●H22OO

SALTSALT

An ionic compound typically formed An ionic compound typically formed fromfrom

reacting an acid with a base.reacting an acid with a base. The term halogen means “salt-The term halogen means “salt-

former”former”