2 - 1CH110

Chapter 4: Atoms & Elements

Elements & Symbols

The Periodic Table

Atomic Structure

Isotopes

Electron Energy Levels

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

Atomic Symbols

BromineNickelHydrogen Nitrogen

Aluminum

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Atomic Symbols

The original name is often of Latin or Greek origin

Potassium (Kalium)

Lead (Plumbum)

Sodium (Natrium)

Iron(Ferrum)

Silver (Argentum)

Gold (Aurum)

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

Atomic Symbols

ChlorineChromiumCalcium

Carbon

Cobalt Copper (Cu)

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Periodic Table: Groups

H

Li

Na

Cs

Rb

K

TlHgAuHfLsBa

Fr

PtIrOsReWTa

He

RnAtPoBiPb

Be

Mg

Sr

Ca

CdAgZrY PdRhRuTcMoNb

AcRa

ZnCuTiSc NiCoFeMnCrV

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

Alkali Metals

Alkaline Earth MetalsAlkaline Earth Metals Halogens

Halogens

Noble gases

Noble gases

3 - 16

III A IV A V A VI A VIIA

VIIIA

II A

Transition Metals

Transition Metals

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He

Rn

XeI

KrBrSe

ArClS

NeFO

P

NC

H

Li

Na

Cs

Rb

K

TlHgAuHfLsBa

Fr

PtIrOsReWTa PoBiPb

Be

Mg

Sr

Ca

CdAgZrY PdRhRuTcMoNb

AcRa

ZnCuTiSc NiCoFeMnCrV

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

Periods areassigned numbers

3 - 15

Periodic Table: Periods

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At

Te

As

Si

B

He

Rn

XeI

KrBrSe

ArClS

NeFO

P

NC

H

Li

Na

Cs

Rb

K

TlHgAuHfLsBa

Fr

PtIrOsReWTa PoBiPb

Be

Mg

Sr

Ca

CdAgZrY PdRhRuTcMoNb

AcRa

ZnCuTiSc NiCoFeMnCrV

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

MetalsMetals Lustrous, malleable and ductile.

Conductors (heat & electricity)

Solids at room temp (except Hg)

Lose electrons to non-metals.

Lustrous, malleable and ductile.

Conductors (heat & electricity)

Solids at room temp (except Hg)

Lose electrons to non-metals.

2 - 9CH110

He

Rn

XeI

KrBrSe

ArClS

NeFO

P

NC

H

Li

Na

Cs

Rb

K

TlHgAuHfLsBa

Fr

PtIrOsReWTa PoBiPb

Be

Mg

Sr

Ca

CdAgZrY PdRhRuTcMoNb

AcRa

ZnCuTiSc NiCoFeMnCrV

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-metalsNon-metals

Gas, liquid, solid (dull, brittle)

Poor conductors = Insulators

Many are diatomic molecules.

Gain e’s from metals

Share e’s with other non-metals

Gas, liquid, solid (dull, brittle)

Poor conductors = Insulators

Many are diatomic molecules.

Gain e’s from metals

Share e’s with other non-metals

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He

Rn

XeI

KrBrSe

ArClS

NeFO

P

NC

H

Li

Na

Cs

Rb

K

TlHgAuHfLsBa

Fr

PtIrOsReWTa PoBiPb

Be

Mg

Sr

Ca

CdAgZrY PdRhRuTcMoNb

AcRa

ZnCuTiSc NiCoFeMnCrV

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

MetaloidsMetaloids

Intermediate properties

Semi conductors

Intermediate properties

Semi conductors

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H

Li

Na

Cs

Rb

K

TlHgAuHfLsBa

Fr

PtIrOsReWTa PoBiPb

Be

Mg

Sr

Ca

CdAgZrY PdRhRuTcMoNb

AcRa

ZnCuTiSc NiCoFeMnCrV

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

MetaloidsMetaloids

MetalsMetals Non-metalsNon-metals

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A model of matter

Atom - 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)

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& neutrons

Structure of the atom Nucleus =

Small, dense, + charge in the center of an atom.

contains

protons +

+

++

+ +

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Structure of the atom Nucleus

Electrons

- charged particles that surround the nucleus.

Electrons move around nucleus in orbitals.

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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.

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The atomic symbol

XA

Z

A = Atomic mass (amu)

= # protons + # neutrons

Z = Atomic number

= # protons = # electrons

++

++

+ +

-

-

---

-

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The atomic symbol

X12

6

A = Atomic mass

= # protons + # neutrons

Z = Atomic number

= # protons = # electrons

++

++

+ +

-

-

---

-

6 6

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The atomic symbol

C12

6

A = Atomic mass

= # protons + # neutrons

Z = Atomic number

= # protons = # electrons

++

++

+ +

-

-

---

-

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The atomic symbol

Na23

11

A = Atomic mass = p + n = 23

Z = Atomic # = p = 11

Sodium

Ag107.87

Silver47 Atomic number

Name of the element

Elemental Symbol

Atomic mass (weight)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 #?

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Isotopes of HydrogenIsotopes = Atoms of the same element but

having different masses.

11

21

31

+

H H H

-

+

-+

-

Protium99.99%

Deuterium0.01%

TritiumTrace %

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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

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++

++

+ +

Isotopes of Carbon

-

Average Atomic weight of C= 12.011 amu

98.89%

C612 C6

13C6

14

++

++

+ +

-

1.11%

++

++

+ +

-

Trace %

-

-

-

-- -

-

- -

-

-

-

--

-

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Radioactive Isotopes

C614

++

++

+ +

-

-

-

--

-

31

+

H

-

Nucleus is unstableSo falls apart (decays)

Giving radioactive particles

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The atomic symbol & isotopes

Determine the number of protons, neutrons and electrons in each of the following.

P3115 Ba

138 56 U

238 92

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Atomic Structure

Symbol At# Mass P N e-

____ ____ ____ 4 5 ___

Cl ____ 37 ___ ___ ___

Si ____ ____ ___ 14 ___

Be 4 9 4

17 17 20 17

14 28 14 14

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Electron arrangement

28

1832

Electronsfill layers

around nucleusLow High

Electronsfill layers

around nucleusLow High

Shells = Energy levels

2412Mg

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

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

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11H

73Li

42He

IAIA IIAIIA

94Be

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115 B

11H

73Li

IAIA IIAIIA IIIAIIIA

94Be

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115 B

126 C

137 N

IIIAIIIA IVAIVA VAVA

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11H

73Li

42He

94Be 20

10Ne

2311Na

2412Mg

4018Ar

IAIA IIAIIA VIIIAVIIIA

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33

2412Mg

11H

73Li

2311Na

94Be

115 B

2713Al

Valence electronsWhere most chemical

Reactions occur.

11

22

Inner electrons: No rxns if normal conditions.Inner electrons: No rxns if normal conditions.

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Inner vs. valence electrons

Valence electronsThis is wheremost chemicalreactionsoccur.

Inner electronsNot much happenshere under normalconditions.

With added energy inner electrons jump to higher levels, then fall back giving E

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11H

73Li

42He

94Be 20

10Ne

2311Na

2412Mg

4018Ar

8811

22

2 - 35CH110

11H

73Li

2311Na

Electron dot (Lewis) Structures

Show only Valence

Electrons

H

Li

Na

K