Review of Chemistry 20

REVIEW OF CHEMISTRY 20

What you really need to remember !

Review Topics Metric System Lab safety (WHMIS, household symbols) Nomenclature (inorganic, organic) Quantum Theory

METRIC SYSTEM

SI BASE UNITSQuantity Base Unit Symbollength metre mmass gram gvolume litre Ltemperature kelvin Ktime second samount of matter mole molelectric current ampere Aluminous intensity candela cd

SI DERIVED UNITSQuantity Name of Unit Symbol in SI Base

Units

density kilogram per kg · m-3 kg · m-3 cubic metre

(kg/m3)

force Newton N kg · m · s-2 (kg · m /

s2)

pressure Pascal Pa N · m-2

(kg·s-2·m-1 , N / m2)

heat energy Joule J N · m (kg·m2·s-2 )

SI PrefixesPrefix Symbol Multiplication Factor Exponential

Notationexa E 1 000 000 000 000 000 000 1018 peta P 1 000 000 000 000 000 1015

tera T 1 000 000 000 000 1012

giga G 1 000 000 000 109

mega M 1 000 000 106

kilo k 1 000 103

hecto h 100 102

deca da 10 101

THE BASE UNIT 1 100

SI PrefixesPrefix Symbol Multiplication Factor Exponential

NotationTHE BASE UNIT 1 100

deci d 0.1 10-1

centi c 0.01 10-2

milli m 0.001 10-3

micro μ 0.000 001 10-6

nano n 0.000 000 001 10-9

pico p 0.000 000 000 001 10-12

femto f 0.000 000 000 000 001 10-15 atto a 0.000 000 000 000 000 001 10-

18

The Metric System These tables must be memorized. The quiz will be on ......

Hazardous Materials in the Home The eight-sided outline

(octagonal) signifies that the contents of the container is dangerous.

The triangular outline signifies that the container is dangerous, usually because the contents are under high pressure.

Hazardous Materials in the HomePoison poisons can enter the body in one of

three ways:a) ingestion (eating)b) inhalation (breathing)c) absorption through the skind) injection

Corrosive are chemicals which can act on clothing,

skin, eyes or internally by drinking or eating can cause symptoms ranging from mild rash

to serious skin damage can damage clothing can cause blindness can cause death if ingested

Flammable are substances which can burn easily or

cause other materials to burn

Radiation radioactive materials emit high energy

atomic particles or high energy radiation (x-rays, gamma rays), or both

found in smoke detectors and involve no danger if kept at a safe distance

Explosive

can cause injury or death as a result a blast or because of the materials expelled by the blast (metal shards)

usually are pressurized aerosol containers which may explode when heated

WHMIS

Workplace Hazardous Materials

Information System

Class A - Compressed Gas

danger lies in the pressure, not in the contents.

Class B - Combustible and Flammable Material

may burn at relatively low temperatures, burn

spontaneously or as a result of heat, sparks or friction

hydrocarbons and several chemicals like phosphorus, sodium and calcium carbide would be included in the list.

Class C - Oxidizing Material

may cause a fire, react violently or explode when it comes into contact with combustible materials such as wood.

an oxidizer supplies the oxygen for a chemical reaction.

Class D, Division 1 – Poisonous and Infectious

Material; Immediate and Serious Toxic Effects

these substances have acute toxicity - refers to

a substance which has immediate effects, usually within 24 hours

Class D, Division 2 – Poisonous and Infectious Material; Other Toxic Effects

these substances have chronic toxicity - refers to the

effects of a substance through repeated exposure at low levels over a long period (weeks, months or years).

effects include; organ damage, illness or death the effects can also include cancer,

allergies or chronic diseases (bronchitis, emphysema, cirrhosis of the liver, etc.)

long term alcohol or cigarette use would fall under this category

Class D, Division 3 – Poisonous and Infectious Material; Biohazardous Infectious Material

refers to an infectious agent

(bacteria, virus or some other organism) which may spread disease if improperly handled, also called a biohazard

this symbol is common in hospital emergency rooms on containers where used needles and dressings are deposited

Class E - Corrosive Material

causes severe eye and skin irritation upon contact causes severe tissue damage with prolonged

exposure may be harmful if inhaled the effects are the same as under the household

hazards

Class F - Dangerously Reactive Material is very unstable may react with water to release

a toxic or flammable gas may explode as a result of shock,

friction or increase in temperature undergoes vigorous polymerization all of these reactions happen very quickly; you

have to be extremely careful around these substances

Lab Procedures and Rules1. No eating or drinking in the lab.

2. Treat all chemicals as if they were hazardous:3. Never perform unauthorized experiments.4. Report all accidents immediately. 5. If you get a chemical solution in your eye go to the eyewash

station immediately and wash the eye for at least 5 minutes.6. If you get chemicals on your clothes, wash the clothes

thoroughly.7. Do not wear loose clothing during a lab. Tie long hair back.8. Do not sit on the lab bench; you do not know how clean it is.9. Clean all equipment thoroughly and put it back where it

belongs.10. Follow directions concerning the safe disposal of chemicals

and solutions.11. Clean your lab station thoroughly after a lab.

In Case of An Accident: Inhaled Poison - Remove the patient to fresh air and apply

artificial respiration if necessary. Keep the victim warm with blankets.

Contact of Poison with Skin or Eyes - Flood affected area with water, for at least 5 minutes. Remove contaminated clothing. DO NOT attempt to use chemical antidote.

Swallowed Poison - If the person is conscious and able to swallow, immediately dilute the poison by giving the victim 2 to 4 cups of milk or water.

Swallowed Corrosives - DO NOT INDUCE VOMITING. Give milk and water. If vomiting occurs naturally, hold head below hips to avoid choking.

Laboratory Equipment Be able to identify the items on the

sheet given. Note: the flask is an erlenmeyer flask

NOMENCLATURE

Types of Chemical Substances Inorganic

elements molecular ionic

Organic aliphatic cyclic substituted

Common substances inorganic or organic

Naming must be simple as possible must be unique

Elements one kind of atom most are monoatomic (one atom)

Cu, Fe, Al, He 8 elements are diatomic (2 atoms)

H2 N2 O2 F2 Cl2 Br2 I2 (At2) 2 are polyatomic

S8

P4

Common Substances known by names other than their

systematic names be familiar with

formulas systematic name common name

know whether systematic or common name takes precedence

Common SubstancesFormula Chemical Name Common Name

H2O hydrogen oxide waterNaCl sodium chloride table saltHCl hydrogen chloride hydrochloric acidHNO3 hydrogen nitrate nitric acidH2SO4hydrogen sulfate sulfuric acidH3PO4hydrogen phosphate phosphoric acidCH3COOH acetic acid vinegarCaSO4 calcium sulfate gypsum (dry wall)NH3 nitrogen trihydride ammonia

Common SubstancesFormula Chemical Name Common Name

H2O2 hydrogen peroxide hydrogen peroxideC2H5OH ethanol drinking alcoholCH3OH methanol wood alcoholCH4 methane natural gasO3 ozone ozoneC12H22O11 sucrose table sugarKCl potassium chloride potashNaOH sodium hydroxide lye, caustic sodaCaO calcium oxide lime

Molecular Compounds made up of 2 non-metals bound

together with covalent bonds:

Molecular Compounds can’t predict formula so naming is done on

a numbering system. prefixes in front of the element name tell

you how many of that element are present in the compound:

mono 1 hexa 6di 2 hepta 7tri 3 octa 8tetra 4 nona 9penta 5 deca

10

Molecular Compounds N2O5

dinitrogen pentaoxide (note ending) CO2

carbon dioxide (no mono on first atom)

COcarbon monoxide

Cl2O7

dichlorine heptaoxide

-idesC carbide Cl chlorideN nitride As arsenideO oxide Se selenideF fluoride Br bromideSi silicide Te tellurideP phosphide I iodideS sulfide

Molecular Compounds tetraphosphorus decaoxide

P4O10 tetrasulfur tetranitride

S4N4 bromine monofluoride

BrF diarsenic triselenide

As2Se3

Ionic Compounds made up of cations and anions which

come together as a result of ionic attraction:

Ionic Compounds there is no molecule, rather a crystal

lattice. chemical formula is ratio of cations to

anions in crystal; formula unit ionic substances are recognized

because they contain a metal + non-metal

Writing Formula Units the formula unit of any ionic compound

is the ratio of cations to anions in the crystal lattice.

the net charge of a formula unit is zero. it is written as the lowest ratio of

cations to anions.

Examples K1+ F1- gives KF Mg2+Cl1- gives MgCl2 Al3+ S2- gives Al2S3 Ca2+ S2- gives CaS Sr2+ OH1- gives Sr(OH)2 NH4

1+ SO42- gives (NH4)2SO4

Do first half of nomenclature assignment

Using Ion Charge to Predict Formulasa) K1+, Br1- f) Zn2+ , O2-

KBr ZnOb) Ca2+, Cl1- g) Mg2+ , NO3

1-

CaCl2Mg(NO3)2c) Li1+, H1- h) Fe2+, O2-

LiH FeOd) Fe3+, OH1- i) Fe3+ , O2-

Fe(OH)3 Fe2O3e) Ca2+, OH1- j) Sn4+, F1-

Ca(OH)2 SnF4

k) Hg2+, O2- p) Mn7+ , O2-

HgOMn2O7l) K1+, PO4

3- q) Na1+, SeO32-

K3PO4 Na2SeO3m) Si4+, O2- r) Na1+, SeO4

2-

SiO2 Na2SeO4n) NH4

1+, SO42- s) Al3+, SO4

2-

(NH4)2SO4 Al2(SO4)3o) Na1+, PO4

3- t) H1+, S2-

Na3PO4 H2S

Using Formulas to Predict Ion Charge a) ZnSO4 f) KSCN

Zn2+ SO42- K1+ SCN1-

b) Mn(NO3)3 g) Na2SO3Mn3+ NO3

1- Na1+ SO32-

c) SnO h) Al2(Cr2O7)3Sn2+ O2- Al3+ Cr2O7

2-

d) LiHCO3 i) MgC2O4Li1+ HCO3

1- Mg2+ C2O42-

e) Hg2Cl2 j) SrH2Hg2

2+ Cl1- Sr2+

H1-

Simple Ionic Compounds cations from groups 1 & 2, Al, Zn, Ag, Cd,

NH41+ (all have only one possible charge)

anions can be anything on the chart (including polyatomic ions)

only one formula unit possible, so name is a repetition of the ion names:

NaClNa1+ Cl1-

sodium chloride

Simple Ionic Compounds NH4NO3

NH41+ NO3

1-

ammonium nitrate

Al2(CO3)3Al3+ CO3

2-

aluminum carbonate

Ag3PAg1+ P3-

silver phosphide

Simple Ionic Compounds cadmium chlorite

Cd2+ ClO21-

Cd(ClO2)2 strontium nitride

Sr2+ N3-

Sr3N2

Stock System used when the cation can have more

than one possible charge used for all other metals on the Periodic

Table. the name of the compound includes the

charge of the cation in roman numerals, in brackets after the cation name.

The Stock System of NomenclatureFormul

aCharge of

CationCharge of

AnionName of

CompoundSnF2 Sn2+ F1- Tin (II) fluoride

SnF4 Sn4+ F1- Tin (IV) fluorideCo(ClO)

3Co3+ ClO1- Cobalt (III)

hypochloriteMnO2 Mn4+ O2- Manganese (IV)

oxideUS3 U6+ S2- Uranium (VI)

sulfide

Classical System older system much, much, older largely replaced by Stock system, but is

still around. if see name be able to give formula. never give classical name for any

formula.

The Stock and Classical Systems of Nomenclature

Formula

Charge of

CationCharge of Anion Stock Name Classical

Name

SnF2 Sn2+ F1- Tin (II) fluoride

Stannous fluoride

SnF4 Sn4+ F1- Tin (IV) fluoride

Stannic fluoride

CoCl2 Co2+ Cl1- Cobalt (II) chloride

Cobaltous chloride

CoCl3 Co3+ Cl1- Cobalt (III) chloride

Cobaltic chloride

Cu2O Cu1+ O2- Copper (I) oxide

Cuprous oxide

CuO Cu2+ O2- Copper (II) oxide

Cupric oxide

Waters of Hydration water molecules physically attached to

ionic and molecular substances. name and formula recognizes their

presence.

Waters of Hydration gypsum typically attracts 4 water

molecules per formula unit:

CaSO4 · 4 H2O

name the substance then use a numbering prefix followed by subscript hydrate:

calcium sulfate tetrahydrate

Naming Hydrated Compounds

Formula Name of Compound

P2O5 · 10 H2O diphosphorus pentaoxide decahydrate

Na2CO3 · H2O sodium carbonate monohydrate

Complete second half of nomenclature assignment

1) NH3 ammonia2) Fe(NO3)2 Fe2+ NO3

1- iron (II) nitrate3) SO2 sulfur dioxide4) MgBr2 Mg2+ Br1- magnesium bromide5) GeCl4 Ge4+ Cl1- germanium (IV) chloride6) N2 nitrogen7) AlPO4 Al3+ PO4

3- aluminum phosphate8) C2H5OH ethanol9) Li2CrO4 Li1+ CrO4

2- lithium chromate10) KH K1+ H1- potassium hydride11) CuCr2O7 Cu2+ Cr2O7

2- copper (II) dichromate12) NH4NO3 NH4

1+ NO31- ammonium nitrate

13) H2SO4 H1+ SO42- sulfuric acid

14) Pb3(PO4)2 Pb2+ PO43- lead (II) phosphate

15) KSCN H1+ SCN1- potassium thiocyanate

16) CO2 carbon dioxide17) P2O5 6 H2O diphosphorus pentaoxide hexahydrate18) PbO Pb2+ O2- lead (II) oxide19) BaS Ba2+ S2- barium sulfide20) S8 sulfur21) Mo(NO3)7 Mo7+ NO3

1- molybdenum (VII) nitrate22) BaH2 Ba2+ H1- barium hydride23) CaSO4 4 H2O

Ca2+ SO42- calcium sulfate

tetrahydrate24) O2 oxygen25) Al2O3 Al3+ O2- aluminum oxide26) PCl3 phosphorus trichloride27) NO3 nitrogen trioxide28) Mn2O3 Mn3+ O2- manganese (III) oxide29) U(CO3)3 U6+ CO3

2- uranium (VI) carbonate30) SnSO3 Sn2+ SO3

2- tin (II) sulfite

1) sodium fluoride Na1+ F1-

NaF2) potassium carbonate K1+ CO3

2-

K2CO33) aluminum sulfide Al3+ S2-

Al2S34) calcium bromide Ca2+ Br1-

CaBr25) chlorine heptafluoride ClF76) silver oxide Ag1+ O2- Ag2O7) ammonium sulfide NH4

1+ S2-

(NH4)2S8) barium hydroxide Ba2+ OH1-

Ba(OH)29) phosphorus P410) mercurous chloride Hg2

2+ Cl1-

Hg2Cl211) tin (II) nitrate Sn2+ NO3

1- Sn(NO3)212) potassium bisulfite K1+ HSO3

1-

KHSO313) caustic soda Na1+ OH1- NaOH14) boric acid H1+ BO3

3- H3BO315) cupric sulfate Cu2+ SO4

2- CuSO4

16) calcium carbonate Ca2+ CO32- CaCO3

17) ammonium sulfite NH41+ SO3

2- (NH4)2SO318) iron (II) hydroxide Fe2+ OH1- Fe(OH)219) uranium (VI) nitrateU6+ NO3

1- U(NO3)620) ozone O321) lithium dichromate Li1+ Cr2O7

2- Li2Cr2O722) hydrogen nitrate H1+ NO3

1- HNO323) barium bicarbonate Ba2+ HCO3

1- Ba(HCO3)224) nitrogen dioxide NO225) carbon monoxide CO26) methanol CH3OH27) ammonium oxalate NH4

1+ C2O42-

(NH4)2C2O428) argon octafluoride ArF829) gold (III) nitrate Au3+ NO3

1- Au(NO3)330) cobalt (II) chloride Co2+ Cl1- CoCl2 · 6 H2O

hexahydrate

Organic Nomenclature 3 types of organic compounds

important for this class: aliphatic hydrocarbons - chains cyclic hydrocarbons - rings aromatic hydrocarbons - benzene rings

Organic Nomenclature Naming hydrocarbons involves looking at 3 aspects:

1. Number of carbons linked in a continuous chain.

2. The presence of single, double or triple bonds in the carbon chain.

3. The presence of structures other than hydrogen attached to the main carbon chain (functional groups).

1. Length of Carbon Chain how many carbons are bonded in a chain

gives the prefix of the name:

1 meth- 7 hept-2 eth- 8 oct-3 prop- 9 non-4 but- 10 dec-5 pent- 11 undec-6 hex- 12 dodec-

1. Length of Carbon Chain other prefixes include:

13 tridec- 30 triacont-14 tetradec- 40 tetracont-15 pentadec- 50 pentacont-20 eicos- 100 hect-25 pentacos-

2. Family Background carbon atoms make 4 chemical bonds. carbon atoms can be linked to each

other by one pair of electrons (single bond), two pair (double bond), or three pair (triple bond).

the presence of double or triple bonds on the carbon chain changes the chemical family.

2. Family Background alkanes

all carbons are connected by single bonds the suffix –ane is added to the name of the

compound the general formula is CnH2n+2

hexane

alkenes the carbon chain contains at least one

double bond the suffix –ene is added to the name of the

compound the general formula is CnH2n

propene

alkynes the carbon chain contains at least one

triple bond the suffix –yne is added to the name of the

compound the general formula is CnH2n-2

propyne

Isomers is defined as the structure associated

with a chemical formula. for many organic compounds it is

possible to have more than one isomer for a given formula.

the simplest isomers are alkenes and alkynes where the double or triple bond can have more than one location:

C4H8

1-butene

2-butene

number the carbons from the end closest to the multiple bond:

Isomers 1- hexene

the double bond is located closest to the left-hand side, so that is where numbering starts.

Isomers

2-hexene

the double bond is closer to the right-hand side, so numbering begins there.

Isomers

1-hexene

1-hexene

these two are the same molecule.

C4H6

1-butyne

2-butyne

Functional Groups hydrocarbon chains halogens alcohols

Functional Groups Hydrocarbon chains are carbon chains

attached to the main chain:

this is calledmethylbutane

Functional Groups Prefixes are used to indicate the

number of carbons in the chain: 1 carbon - methyl- 2 carbons - ethyl- 3 carbons - propyl-

Functional Groups when it is possible to attach the

hydrocarbon in more than 1 place numbering is used:

2-methylpentane

Functional Groups

3-methylpentane

4-methyl-2-pentene

Functional Groups 2,3-dimethylpentane

Functional Groups 3,4-dimethyl-2-pentene

Functional Groups 2,4-dimethyl-3-ethylpentane

Functional Groups

Functional Groups Halogens - group 17 elements

attached to the carbon chain:

1-fluoro-3-chloropentane

Functional Groups

1-fluoro-1,1-diiodo-5,5,5-trichloro- 2-pentyne

Functional Groups Alcohols - are formed when –OH

groups are attached to the main chain:

1-pentanol

Functional Groups

2-penten-1-ol

Cyclic and Aromatic Hydrocarbons cyclopropane

Cyclic and Aromatic Hydrocarbons cyclohexane

Cyclic and Aromatic Hydrocarbons cyclohexene

2-chloro-4-fluorocyclohexene

Cyclic and Aromatic Hydrocarbons benzene

Cyclic and Aromatic Hydrocarbons phenol

Cyclic and Aromatic Hydrocarbons toluene

Cyclic and Aromatic Hydrocarbons dichlorobenzene

ortho- meta- para-

Complete organic nomenclature assignment

Quantum Mechanics and Atomic Orbitals

Quantum mechanics is a mathematical treatment into which both the wave and particle nature of matter could be incorporated.

Quantum Mechanics since the electron is both

a wave and a particle it is impossible to give it’s location or speed with certainty.

gives a probability density map of where an electron has a certain statistical likelihood of being at any given instant in time.

Quantum Numbers The probability map reveals the

atomic orbitals, and their corresponding energies.

An orbital is described by a set of three quantum numbers.

Principal Quantum Number, n

This relates to the energy of the electron

As n becomes larger, the atom becomes larger and the electron is further from the nucleus.

This is directly related to the period of the atom on the Periodic Table

Angular momentum quantum number, l

This quantum number depends on the value of n.

The values of l begin at 0 and increase to n – 1.

Theoretical g, h, i, etc. orbitals exist, but no atoms have been created to use them.

This quantum number defines the shape of the orbital.

Value of l 0 1 2 3

Type of orbital s p d f

Magnetic Quantum Number, ml

This quantum number depends on l. The magnetic quantum number has

integer values between –l and +l. Magnetic quantum numbers give the

three-dimensional orientation of each orbital.

s Orbitals Value of l = 0. Spherical in shape. Radius of sphere

increases with increasing value of n.

s Orbitals

p Orbitals Value of l = 1. Have two lobes with a node between

them.

d Orbitals Value of l is

2. Four of the

five orbitals have 4 lobes; the other resembles a p orbital with a doughnut around the center.

f orbitals

Spin Quantum Number, ms

electrons have spin, which creates a magnetic field

there are two spin states possible, +1/2 and -1/2

a single orbital can hold a maximum of two electrons, which must have opposite spin.

Pauli Exclusion Principle No two electrons in

the same atom can have exactly the same energy.

For example, no two electrons in the same atom can have identical sets of quantum numbers.

Electron Address thus every electron location is defined

in terms of 4 things:a) Principal Quantum Number - 1 to 7b) Angular Quantum Number – s, p, d or fc) Magnetic Quantum Number – implied by

number of electrons in each shape; s has 2, p has 6, d has 10 and f has 14

d) Spin Quantum Number – why each orbital can contain 2 electrons

Electron Configurations Electrons tend to occupy the lowest available

orbital. The simplest atom, hydrogen has 1 electron. In its’ lowest, or ground state, this electron will occupy

the 1s orbital, the lowest energy orbital available (see chart, page 105)

The next element, helium, has two electrons, both of which will occupy the 1s orbital.

Element three, lithium, has three electrons. The first two will fill the 1s orbital while the third must move up to the next energy level, 2s.

Thus the electron configuration of an atom is the arrangement of the electrons from the lowest energy level to the highest.

Electron Configurations Consist of

Number denoting the energy level. Letter denoting the type of orbital. Superscript denoting the number of

electrons in those orbitals. For instance:

Iron (Fe) – contains 26 electrons 1s22s22p63s23p64s23d6

watch the order of filling

Electron Configuration Potassium - 19 electrons

1s22s22p63s23p64s1

Silver - 47 electrons 1s22s22p63s23p64s23d104p65s24d9

Tungsten - 74 electrons 1s22s22p63s23p64s23d104p65s24d105p66s24

f145d4

Plutonium - 94 electrons 1s22s22p63s23p64s23d104p65s24d105p66s24

f145d10

6p67s25f6

Write the correct electron configuration for the following: Si, S, P, Ca, As, Fe, Br, Kr, At, U, Na1+,

F1-, Ne

Electron Configuration Si - 14 e1- 1s22s22p63s13p3

S - 16 e1- 1s22s22p63s23p4

P - 15 e1- 1s22s22p63s23p3

Ca - 20 e1- 1s22s22p63s23p64s14p1 As - 33 e1- 1s22s22p63s23p64s23d104p3

Fe - 26 e1- 1s22s22p63s23p64s23d6

Br - 35 e1- 1s22s22p63s23p64s23d104p5

Kr - 36 e1- 1s22s22p63s23p64s23d104p6

At - 85 e1-

1s22s22p63s23p64s23d104p65s24d105p66s24f145d106p5

U - 92 e1- 1s22s22p63s23p64s23d104p65s24d105p66s24f145d106p67s25f4

Na1+ - 10 e1- 1s22s22p6

F1- - 10 e1- 1s22s22p6

Ne - 10 e1- 1s22s22p6

Electron Promotion promotion of an outer ‘s’ electron to the

adjacent ‘p’ orbital. turns non-bonding electrons into

bonding electrons allows atoms to make more chemical

bonds and achieve a lower energy applies to elements from groups 2, 13

and 14 only for these elements promotion is the

rule

Electron PromotionElement Unhybridized

Hybridized

beryllium 1s22s2 1s22s12p1

boron 1s22s22p1 1s22s12p2

carbon 1s22s22p2 1s22s12p3

Orbital Diagrams are another way to illustrate the position of

electrons. They are best learned by comparison with

electron configuration: Na (11 protons, 11 electrons) electron configuration: 1s22s22p63s1

orbital diagram:

1s 2s 2p 3s

↑↓ ↑↓ ↑↓ ↑↓ ↑↓ ↑

Orbital DiagramsRepresentative

Group Element Electron configuration Orbital Diagram

1s 2s 2p 1 lithium 1s22s1 ↑↓ ↑

2 beryllium 1s22s12p1 ↑↓ ↑ ↑

13 boron 1s22s12p2 ↑↓ ↑ ↑ ↑

14 carbon 1s22s12p3 ↑↓ ↑ ↑ ↑ ↑

15 nitrogen 1s22s22p3 ↑↓ ↑↓ ↑ ↑ ↑

16 oxygen 1s22s22p4 ↑↓ ↑↓ ↑↓ ↑ ↑

17 fluorine 1s22s22p5 ↑↓ ↑↓ ↑↓ ↑↓ ↑

18 neon 1s22s22p6 ↑↓ ↑↓ ↑↓ ↑↓ ↑↓

Repeat the last assignment, giving the orbital diagrams for the elements.

Na1+, F1-, Ne are all the same:

Electron dot (Lewis) diagrams gives information only concerning the valence

electrons. Valence electrons are the electrons on the outside

of an atom; they are the electrons responsible for bonding and are also the electrons gained or lost when an atom ionizes.

Valence electrons are electrons in the s and p orbitals of the highest energy level reached by the electrons of an atom.

In this class when valence electrons are mentioned, the only elements concerned are those in groups 1, 2, and 13 through 18.

Lewis diagrams group 1 group 2 group 13 group 14 group 15 group 16 group 17 group 18

Lewis diagrams Repeat last assignment, making lewis

diagrams.

Lewis Diagram Answers:

Fe and U have no lewis diagrams

What do Orbital and Lewis diagrams tell us? both give information about valence

electrons. if valence electrons are paired, they

cannot be used for bonding with other atoms. They are lone-pair electrons.

unpaired valence electrons are bonding electrons.

5 valence electrons 1 lone pair 3 bonding electrons; this atom makes 3

chemical bonds.


chemical bonds


chemical bond


chemical bonds

Orbital Diagrams Each box represents one

orbital. Half-arrows represent the

electrons. The direction of the arrow represents

the spin of the electron. Pauli Exclusion Principle – no two

electrons in the same orbital can have the same spin

Hund’s Rule“For degenerate orbitals, the lowest energy is attained when the number of electrons with the same spin is maximized.”

Review of Chemistry 20

Documents

Transcript of Review of Chemistry 20