Electron Energy Levels

2 - 1CH104

Chapter 4: Atoms

Elements & Symbols

The Periodic Table

Atomic Structure

Isotopes

Electron Energy LevelsPeriodic Trends

2 - 2CH104

Each element is assigned a unique symbol1-2 letters; 1st is capitalized

Atomic Symbols

BromineNickelHydrogen Nitrogen

Aluminum

2 - 4CH104

Atomic Symbols

The original name is often of Latin or Greek origin

Potassium (Kalium)

Lead (Plumbum)

Sodium (Natrium)

Iron(Ferrum)

Silver (Argentum)Gold (Aurum)

2 - 6CH104

Elements with same starting letter, get second letter added to the symbol

Atomic Symbols

ChlorineChromiumCalcium

CarbonCobalt Copper (Cu)

2 - 8CH104

Modern periodic table

H

Li

Na

Cs

Rb

K

TlHgAuHfLaBa

Fr

PtIrOsReWTa

He

RnAtPoBiPb

Be

Mg

Sr

Ca

CdAgZrY PdRhRuTcMoNb

AcRa

ZnCuTiSc NiCoFeMnCrV

In XeITeSbSn

Ga KrBrSeAsGe

Al ArClSPSi

B NeFONC

I A II A III A IV A V A VI A VIIA VIIIA

III B IVB V B VIB VIIB VIII B IB IIB

1

2

3

4

5

6

7 Gd

Cm

Tb

Bk

Sm

Pu

Eu

Am

Nd

U

Pm

Np

Ce

Th

Pr

Pa

Yb

No

Lu

Lr

Er

Fm

Tm

Md

Dy

Cf

Ho

Es

The periodic tablehelps us understand

• behavior, • reactions• properties

of the elements.

Mendeleev, 1871“Properties of the elements

vary in a periodic manner.”

2 - 9CH104

A row or period

He

Rn

XeI

KrBrSe

ArClS

NeFO

P

NC

H

Li

Na

Cs

Rb

K

TlHgAuHfLaBa

Fr

PtIrOsReWTa PoBiPb

Be

Mg

Sr

Ca


AcRa


In SbSn

Ga Ge

Al

Gd

Cm

Tb

Bk

Sm

Pu

Eu

Am

Nd

U

Pm

Np

Ce

Th

Pr

Pa

Yb

No

Lu

Lr

Er

Fm

Tm

Md

Dy

Cf

Ho

Es

At

Te

As

Si

B

1

2

3

4

5

6

7

Periods areassigned numbers

2 - 10CH104

Common group names

H

Li

Na

Cs

Rb

K

TlHgAuHfLaBa

Fr

PtIrOsReWTa

He

RnAtPoBiPb

Be

Mg

Sr

Ca


AcRa


In XeITeSbSn

Ga KrBrSeAsGe

Al ArClSPSi

B NeFONC

I A

III B IVB V B VIB VIIB VIII B IB IIB

Gd

Cm

Tb

Bk

Sm

Pu

Eu

Am

Nd

U

Pm

Np

Ce

Th

Pr

Pa

Yb

No

Lu

Lr

Er

Fm

Tm

Md

Dy

Cf

Ho

Es

Alkali Metals

Alkaline Earth MetalsHalogens

Noble gases

III A IV A V A VI A VIIA

VIIIA

II A

Transition Metals

Lanthanides

Actinides

Chalcogens

2 - 11CH104

Why do we have thoserows on the bottom?

H

Li

Na

Cs

Rb

K

LaBa

Fr

Be

Mg

Sr

Ca

Y

AcRa

Sc

TlHgAuHf PtIrOsReWTa

He

RnAtPoBiPb

CdAgZr PdRhRuTcMoNb

ZnCuTi NiCoFeMnCrV

In XeITeSbSn

Ga KrBrSeAsGe

Al ArClSPSi

B NeFONC

Gd

Cm

Tb

Bk

Sm

Pu

Eu

Am

Nd

U

Pm

Np

Ce

Th

Pr

Pa

Yb

No

Lu

Lr

Er

Fm

Tm

Md

Dy

Cf

Ho

Es

This arrangement takes toomuch space and is hard to read.

2 - 12CH104

Names & Symbols

He

Rn

XeI

KrBrSe

ArClS

NeFO

P

NC

H

Li

Na

Cs

Rb

K

TlHgAuHfLaBa

Fr

PtIrOsReWTa PoBiPb

Be

Mg

Sr

Ca


AcRa


In SbSn

Ga Ge

Al

Gd

Cm

Tb

Bk

Sm

Pu

Eu

Am

Nd

U

Pm

Np

Ce

Th

Pr

Pa

Yb

No

Lu

Lr

Er

Fm

Tm

Md

Dy

Cf

Ho

Es

At

Te

As

Si

B

1

2

3

4

5

6

7

Know the names & symbols

2 - 13CH104

At

Te

As

Si

B

He

Rn

XeI

KrBrSe

ArClS

NeFO

P

NC

H

Li

Na

Cs

Rb

K

TlHgAuHfLaBa

Fr

PtIrOsReWTa PoBiPb

Be

Mg

Sr

Ca


AcRa


In SbSn

Ga Ge

Al

Gd

Cm

Tb

Bk

Sm

Pu

Eu

Am

Nd

U

Pm

Np

Ce

Th

Pr

Pa

Yb

No

Lu

Lr

Er

Fm

Tm

Md

Dy

Cf

Ho

Es

Metals Lustrous, malleable and ductile.Conductors (heat & electricity)Solids at room temp (except Hg)

Lose electrons to non-metals.

2 - 14CH104

He

Rn

XeI

KrBrSe

ArClS

NeFO

P

NC

H

Li

Na

Cs

Rb

K

TlHgAuHfLaBa

Fr

PtIrOsReWTa PoBiPb

Be

Mg

Sr

Ca


AcRa


In SbSn

Ga Ge

Al

Gd

Cm

Tb

Bk

Sm

Pu

Eu

Am

Nd

U

Pm

Np

Ce

Th

Pr

Pa

Yb

No

Lu

Lr

Er

Fm

Tm

Md

Dy

Cf

Ho

Es

At

Te

As

Si

B

Non-metals

Gas, liquid, solid (dull, brittle)Poor conductors = InsulatorsMany are diatomic molecules.Gain e’s from metals Share e’s with other non-metals

2 - 15CH104

He

Rn

XeI

KrBrSe

ArClS

NeFO

P

NC

H

Li

Na

Cs

Rb

K

TlHgAuHfLaBa

Fr

PtIrOsReWTa PoBiPb

Be

Mg

Sr

Ca


AcRa


In SbSn

Ga Ge

Al

Gd

Cm

Tb

Bk

Sm

Pu

Eu

Am

Nd

U

Pm

Np

Ce

Th

Pr

Pa

Yb

No

Lu

Lr

Er

Fm

Tm

Md

Dy

Cf

Ho

Es

At

Te

As

Si

B

3 - 11

Metaloids

Intermediate propertiesSemi conductors

2 - 16CH104

H

Li

Na

Cs

Rb

K

TlHgAuHfLaBa

Fr

PtIrOsReWTa PoBiPb

Be

Mg

Sr

Ca


AcRa


In Sn

Ga

Al

Gd

Cm

Tb

Bk

Sm

Pu

Eu

Am

Nd

U

Pm

Np

Ce

Th

Pr

Pa

Yb

No

Lu

Lr

Er

Fm

Tm

Md

Dy

Cf

Ho

Es

He

Rn

XeI

KrBrSe

ArClS

NeFO

P

NC

Sb

Ge

At

Te

As

Si

B

Metaloids

Metals Non-metals

2 - 18CH104

A model of matterAtom - The smallest unit of an

element that is still that element.

Molecule -The smallest unit of a pure substance that is still that substance.

May contain > 1 atom or element.

ie. Aluminum (Al)

ie. Water (H2O)

2 - 19CH104

Structure of the atom Nucleus Small, dense, + charge in the center of

an atom.

contains protons

& neutrons

++

+++ +

2 - 20CH104

Rutherford’s Gold-Foil Experiment 99% of + particles aimed at gold went straight through. A few were deflected. A few bounced back

Conclusion: Atoms are mostly empty space. Atoms have a small, dense nucleus with + charge.

2 - 21CH104

Structure of the atom Nucleus (+)

Electrons - charged particles that surround the nucleus.

Electrons moved around nucleus in orbitals.

2 - 22CH104

Structure of the atom

The nucleus is a small part of an atom.

If the nucleus was the sizeof a marble, the atom wouldfill a football stadium.

The nucleus would weighover 10,000 tons.

2 - 23CH104

Z = Atomic number = # protons = # electrons

The atomic symbol

XA

Z

A = Atomic mass (amu) = # protons + # neutrons

++

+++ +

-

-

---

-

2 - 24CH104

A = Atomic mass = # p + # n

The atomic symbol

XA

Z

C

#

Z = Atomic # # p = # e

C = Charge = + or - values

# = Number of atoms in a formula.

2 - 25CH104

The atomic symbol

X12

6

A = Atomic mass = # protons + # neutrons


++

+++ +

-

-

---

-

6 6

2 - 26CH104

The atomic symbol

C12

6

A = Atomic mass = # protons + # neutrons


++

+++ +

-

-

---

-

2 - 27CH104

The atomic symbol

Na23

11

1+

A = Atomic mass = p + n = 23

Z = Atomic # = p = 11

C = Charge = +1

# = 1 atom in formula.

Sodium

11 12

2 - 28CH104

Ag107.87

Silver47 Atomic number

Name of the element

Elemental Symbol

Atomic mass (weight)

Atomic weight = The average, relative mass of an atom in an element.

Why is the atomic weight on the tables not a whole #?

2 - 29CH104

Isotopes of HydrogenIsotopes = Atoms of the same element but

having different masses.11

21

31

+

H H H

-+

-+

-

Protium99.99%

Deuterium0.01%

TritiumTrace %

2 - 30CH104

Isotopes of HydrogenIsotopes = Atoms of the same element but

having different masses.11

21

31

+

H H H

-+

-+

-

Average Atomic weight of Hydrogen = 1.00794 amu

2 - 31CH104

++

+++ +

Isotopes of Carbon

-

Average Atomic weight of C= 12.011 amu

98.89%

C612 C6

13 C614

++

+++ +

-

1.11%

++

+++ +

-

Trace %

-

--

-- -

-

- -

-

-

-

--

-

2 - 32CH104

Radioactive Isotopes

C614

zzz++

+++ +

-

-

-

--

-31 H

+

-

Nucleus is unstableSo falls apart (decays)

Giving radioactive particles

H-3 C-14

2 - 33CH104

Average Atomic Mass

Cl1737Cl17

35

(75.8)35

75.8% 24.2%

+ (24.2)37

= 35.45 amu100

2 - 35CH104

Symbol Atomic#

Mass Protons Neutrons Electrons

Atomic Structure

Be

1414 1428 14Si

17201717 37Cl

44 9 4 5

Complete the table:

2 - 36CH104

Electronic arrangement

A new layer isadded for each row or period in the table.

2 - 37CH104

Electron arrangement

28

1832

Electronsfill layers

around nucleusLow High

Shells = Energy levels

2412Mg

2 - 38CH104

11H

73Li

42He

IA IIA

94Be

2, 1 2, 2

2 - 39CH104

115 B

11H

73Li

IA IIA IIIA

94Be

2, 1 2, 2 2, 3

2 - 40CH104

115 B 12

6 C137 N

IIIA IVA VA

2, 3 2, 4 2, 5

2 - 41CH104

94Be

11H

73Li

42He

2010Ne

2311Na

2412Mg 40

18Ar

IA IIA VIIIA

2, 1 2, 2

2, 8, 1 2, 8, 2

2, 8

2, 8, 8

2 - 42CH104

3

2412Mg

11H

73Li

2311Na

94Be 11

5 B

2713Al

Valence electronsWhere most chemical

Reactions occur.

1

2

2, 1 2, 2

2, 8, 1 2, 8, 2

2, 3

2, 8, 3

2 - 43CH104

11H

73Li

42He

94Be 20

10Ne

2311Na

2412Mg 40

18Ar

81

2

2, 1 2, 2 2, 8

2, 8, 1 2, 8, 2 2, 8, 8

Octet Rule

2 - 45CH104

An atom is like an inverted pyramid. As you get farther from the nucleus, there is more room for electrons.

1st level holds 2 e’s.2nd level holds 8 e’s.3rd level holds 18 e’s.4th level holds 32 e’s.etc....

Rules for electron Placement

2 e-

8 e-

18 e-

32 e-

++

+

+ ++

2 - 46CH104

Hotel Model

s

s

p

s

p

d

s

p

d

f

n = 4 (4th floor)

n = 3 (3rd floor)

n = 2 (2nd floor)

n = 1 (1st floor)

Each shell (floor of the Hotel) Has subshells (s,p,d,f)

++

+

+ ++

2 - 47CH104

Orbitals

p (3)s (1) d (5)

Each subshell contains orbitals which can hold a maximum of two electrons

f (7)

2 - 48CH104

s

s

ps

pd

sp

df

n = 4

n = 3

n = 2

n = 1

The Aufbau principleElectrons fill from the low high.fill n = 1 before n = 2 , fill s before p ...

Electrons don’t share same orbital unless they need to.

(i.e. no pairing until each orbital of the set has an electron)

Hund’s Rule+

++

+ ++

2 - 49CH104

5d

5s

5p

4d

4f

4s

4p

3d

3s

3p

2s

2p

1s

Major trends in electron filling

Exceptions to Hotel Model:Fill 4s before 3dFill 5d before 4 fFill 5s before 4dFill 6d before 5 f

This is why transition metals are assigned as B group elements.

2 - 54CH104

1s __2s __

2p __ __ __3s __

3p __ __ __4s __ 3d __ __ __ __ __

5s __4p __ __ __

4d __ __ __ __ __ 5p __ __ __

6s __ 5d __ __ __ __ __ 4f __ __ __ __ __ __ __

73Li

1s22s1

Electron Configuration

2 - 55CH104

1s __2s __

2p __ __ __3s __

3p __ __ __4s __ 3d __ __ __ __ __

5s __4p __ __ __

4d __ __ __ __ __ 5p __ __ __

6s __ 5d __ __ __ __ __ 4f __ __ __ __ __ __ __

1s22s22p4

16 8 O


2 - 56CH104

1s __2s __

2p __ __ __3s __

3p __ __ __4s __ 3d __ __ __ __ __

5s __4p __ __ __

4d __ __ __ __ __ 5p __ __ __

6s __ 5d __ __ __ __ __ 4f __ __ __ __ __ __ __

1s22s22p63s23p64s23d10

30Zn

[Ar] 4s23d10

[Ar] 3d104s2


2 - 57CH104

Classification by sublevels

H

Li

Na

Cs

Rb

K

TlHgAuLsBa

Fr

PtIrOsReWTa

He

RnAtPoBiPb

Be

Mg

Sr

Ca

CdAgY PdRhRuTcMoNb

AcRa

ZnCu

Hf

Zr

TiSc NiCoFeMnCrV

In XeITeSbSn

Ga KrBrSeAsGe

Al ArClSPSi

B NeFONC

Gd

Cm

Tb

Bk

Sm

Pu

Eu

Am

Nd

U

Pm

Np

Ce

Th

Pr

Pa

Yb

No

Lu

Lr

Er

Fm

Tm

Md

Dy

Cf

Ho

Es f

s

d

p

3 - 25

2 - 58CH104

Using the periodic tableto find sublevels

Tl RnAtPoBiPb

In XeITeSbSn

Ga KrBrSeAsGe

Al ArClSPSi

B NeFONC

Gd

Cm

Tb

Bk

Sm

Pu

Eu

Am

Nd

U

Pm

Np

Ce

Th

Pr

Pa

Yb

No

Lu

Lr

Er

Fm

Tm

Md

Dy

Cf

Ho

Es

s

23

45

H

Li

Na

Cs

Rb

K

Ba

Fr

He

Be

Mg

Sr

Ca

Ra

6

7

1

23

4

5HgAuHfLa PtIrOsReWTa


Ac

ZnCuTiSc NiCoFeMnCrV345

6

d

6

p

f45

2 - 59CH104

Inner vs. valence electrons

Valence electronsWhere most reactionsoccur.

Inner electronsNot much happenshere under normalconditions.

2 - 60CH104

The Continuous SpectrumWhen sunlight (white light) is passed thru a prism, a continuous rainbow of colors is observed.

There appears to be light of every color in sunlight.

2 - 61CH104

Electromagetic SpectrumThe Continuous Spectrum

2 - 63CH104

The Discrete Spectrum !But when light from elements is passed thru a prism, a continuous spectrum is not observed.

From the red glow of hydrogen, 4 lines emerged.

2 - 64CH104

1 _____

2 _____

3 _____

4 _____

5 _____

6 _____ 11H

Excitation of electrons

Add Energy to kick e- to higher level

1 _____

2 _____

3 _____

4 _____

5 _____

6 _____

E

Energy is given back when e- falls back to lower level

656 nm

486 nm

434 nm

410 nm

Some of these discrete Quantities (Quanta) of Energy appear as colors

2 - 65CH104

Emission Spectrum of Hydrogen

https://www.khanacademy.org/science/chemistry/electronic-structure-of-atoms/bohr-model-hydrogen/v/emission-spectrum-of-hydrogen

Explanation of 4 line spectrum of Hydrogen: (10:49min)




2 - 66CH104

The Discrete Spectrum !

H

Hg

Ne

2 - 68CH104

Group Numbers & Valence Electrons

H

Li

Na

Cs

Rb

K

TlHgAuHfLsBa

Fr

PtIrOsReWTa

He

RnAtPoBiPb

Be

Mg

Sr

Ca


AcRa


In XeITeSbSn

Ga KrBrSeAsGe

Al ArClSPSi

B NeFONC

Gd

Cm

Tb

Bk

Sm

Pu

Eu

Am

Nd

U

Pm

Np

Ce

Th

Pr

Pa

Yb

No

Lu

Lr

Er

Fm

Tm

Md

Dy

Cf

Ho

Es4 - 6

1

2 3 4 5 6 7Representative Elements 8

Periodic trends

2 - 69CH104

11H

73Li

2311Na

Electron-Dot Symbols(Lewis Symbols)

Show only Valence

Electrons

H

Li

Na

K

2 - 70CH104

H

Li

Na

K

He

Be B C O F NeN

Mg

Ca

Al

Ga

Si

Ge

P

As

S

Se

Cl

Br

Ar

Kr

1

2 3 4 5 6 7

8Electron-Dot SymbolsPeriodic trends

2 - 71CH104

Atomic Size

Ba

Sr

Ca

Mg

Be

Tl

In

Ga

Al

B

Pb

Sn

Ge

Si

C

Cs

Rb

K

Na

Li

Bi

Sb

As

P

N

Te

Se

S

C

I

Br

Cl

FH

Atomsgetlargeras you go down a group.

Periodic trendsAtoms get smaller as you go across a period.

2 - 73CH104

At

I

Br

Cl

Po

Te

Se

S

Bi

Sb

As

P

Pb

Sn

Ge

Si

FON

Tl

Na

Cs

Rb

K

Ba

Mg

Sr

Ca

In

Ga

Al

H

Li Be B C

First ionization energyThe energy required to remove the first electron from a neutral atom.

4 - 50© Chemeketa Community College: Chemistry for Allied Health

Periodic trends

2 - 75CH104

ElectronegativityRelative ability of atoms to attract electrons

when they form bonds.

At

I

Br

Cl

Po

Te

Se

S

Bi

Sb

As

P

Pb

Sn

Ge

Si

FON

Tl

Na

Cs

Rb

K

Ba

Mg

Sr

Ca

In

Ga

Al

H

Li Be B C

4 - 50© Chemeketa Community College: Chemistry for Allied Health

Periodic trends

2 - 76CH104

Summary of trends.As atomic size decreasesFirst ionization energy increases.Electrons are harder to remove.Adding more electrons is easier.

SummaryMetals are larger so tend to lose electrons.

Non-metals are smaller so tend to gain electrons.

Periodic trends

Documents

Electron Energy Levels