Notes One Unit EightMolecules

• Cross Word Answers• State the three laws that support the existence of

atoms • List the five principles of Dalton's atomic theory.• Calculate the masses of atoms in amu and gram

units.• Describe how the atomic mass unit was chosen.• Calculate Average Atomic Mass• Reading Assignment Two unit Two Next Class

• http://www.teachersdomain.org/special/nova/nova.physics.ato/

Laws of proportions• What is the proportion for(?)…

• H2O

• H2O2

• N2O3

• N2O5

• N2O

• N2O4

2:1

1:1

2:3

2:5

2:1

1:2

Multiple Proportions

Multiple Proportions

DefiniteProportions

Law of conservation of massDEMO NaOH/HCl phenolphthalein on a balance

NaOH(aq)+ HCl(aq) H2O(l)+ NaCl(aq)

Law of conservation of mass• 2H2(g) + 1O2(g)2H2O(l)• H= H=• O= O=• Mass is conserved!• 3H2(g) + 1N2(g)2NH3(l)• N= N=• H= H=• 2C2H6(g)+ 7O2(g) 4CO2(g) + 6H2O(l)• C= C=• H= H=• O= O=

4 42 2

2 26 6

4 41214 8

12+ 6=14

Three laws that support the existence of atoms

1. Law of definite proportions

2. E=MC2

3. Law of multiple proportions

List the five(Four?) principles of Dalton's atomic theory.• 1. All matter is made of indivisible and

indestructible atoms.

• 2. All atoms of a certain element are identical in mass and properties.

• 3. Compounds can be formed by using two or more different kinds of atoms.

• 4. A chemical reaction is a rearrangement of atoms.

Carbons Mass in amu and gram units

• 1 amu=1/12 C-12

• 1 C-12 mass = 12.00000000 amu

• 1amu = 1.66053X10-24 grams.

• 12.0000000 grams/Mole!

Mass Spectroscope

Neon gas

e-1 beam

heating element negative grid

Ne Ne+1

20Ne+121Ne+1

22Ne+1

Calculating Average Atomic Mass E amu % product

C-12 C-13

12.00000013.003355

98.901.10

= 1186.8= 14.3036905

xx

1187+ 14

1201+ 14.3

118798.90 %+ 1.10 %100.00 %

÷100.00 = 12.01amu4 sd 5 sd 4 sd1201

Notes Two Unit Two The Nucleus

• Describe the evidence for the existence of electrons and their presence in atoms.

• Explain how Rutherford's experiments led to the discovery of the nucleus.

• Discuss atoms of different elements in terms of the numbers of electrons, protons, and neutrons they contain.

Potassium Gas- K(g)e-1 Beam

To Vacuum Pump

K+1 ions

Vacuum Chamber

Magnet Face To Vacuum Pump

39K+140K+1 41K+1

K+1

K

Photographic Plate

Calculating Average Atomic Mass E amu % product

79Br

81Br 78.918337680.9162913

50.697 49.317

= 4000.922961= 3990.548738

xx

+ 3990.54000.950.697 %

+49.317 %100.014 %

÷100.014 = 79.9028136 amu5 sd 6 sd 5 sd

7991.4

7991.4

= 79.903 amu

Cathode Ray Demo

• Electrons(e-1) leave the cathode

Cathodee-1

e-1e-1 e-1

Anode

- +

Cathode Ray Devices

Van de Graff Demo

Van de Graff generator

Leyden Jar

Millikan's oil-drop experiment Charge of e-1 is equal to -1.602189 x 10-19 Coulombs.

X-ray

..

.-1

-2

(+) plate

(-) plate

perfume sprayerOil drops

0

hole

battery

Rutherford's experiments

Characteristics of atoms

Radium

Lead

Gold Foil

Microscope

Alp

ha p

article

+2 8000

10,000 atoms thick

7999 pass through

mostly empty spaceSmall(1/10,000),

42He+2

dense, andheavy

positive charge core

+79

+2

Atoms and their electrons, protons, and neutrons

Proton(P+1) + Neutrons(n0)= Mass #(Z)

A Z Element P+1 n0 Symbol Name

HydrogenH111 0Hydrogen1 1

1 2 Hydrogen 1 1 H21 Hydrogen

1 3 Hydrogen 1 2 H31 Hydrogen

8 16 Oxygen 8 8 O168 Oxygen

26 57 Iron 26 31 Fe5726 Iron

-1-2-3

-16-57

Nuclear Reactions A reaction, as in fission, fusion, or radioactive decay, that

alters the energy, composition, or structure of an atomic nucleus.

23592U + n 1

0 Xe +13554 + n1

0Sr 10038

Fission:

Fusion:10n+ 7

3Li 31H

42+ He + 1

0n

Decay:

23892 U 234 Th +90

42He Alpha Decay

23490Th 234

91Pa + 0-1 Beta Decay(e-1)

Atomic Particles

Particle Symbol ChargeMass

(g)Mass(amu)

Family

proton p+ +1 1.673 x 10-24 1.00727 baryon

neutron n0 0 1.675 x 10-24 1.00866 baryon

electron/positron

e-/e+ -1/+1 9.109 x 10-28 5.485 x 10-4 lepton

neutrino        0 < 10-32 < 5 x 10-9 lepton

photon    0 0 0 photon

Notes Three Unit Eight The Structure of the Atom’s Shell

• Describe the nature of light and how it is produced. • Explain how the wavelengths of light emitted by an atom

provide information about electron energy levels. • Flame Tests Lab B

Atomic ModelRutherford model*Mostly Empty Space

Very Small,Very Dense,Positive Charged,

*Nucleus…

Where were the electrons?What are the electrons doing?

+

Particle Model of The ElectronNeils Bohr

e-1 found in the empty space.He used light to define their actions.

e-1 region

+

Electromagnetic Spectrumgamma

rayX-ray UV IR radar FM TV

Shortwave AM

Visible Light

Short wavelength

Long wavelength

Low Energy

High Energy

Bohr’s Model of the shell *Particle Model

*Circular orbits

* Hydrogen only

Light’s Energy

e-1

The Spectroscope

Helium Tube

slit

Prism

spectrograph

Bright-lineEmissionSpectrum

Solar Spectrum

• hydrogen

• helium

• mercury

• uranium

(92 elements)

Spectrum Example #1

n=1

n=2

n=3

n=4

n=5n=6

energy

RedOrange

YellowGreenBlueindgoViolet

Ground State

Excited State

Quantum Amount

Spectrum Example #2

n=1

n=2

n=3

n=4

n=5n=6

energy

RedOrange

YellowGreenBlueindgoViolet

Ground State

Excited State

Quantum Amount

Spectrum Example #3

n=1

n=2

n=3

n=4

n=5n=6

energy

RedOrange

YellowGreenBlueindgoViolet

Ground State

Excited State

Quantum Amount

Spectrum Example #4

n=1

n=2

n=3

n=4

n=5n=6

energy

RedOrange

YellowGreenBlueindgoViolet

Ground State

Excited State

Quantum Amount

Identifying Elements with Flame Tests

Na K Li Ba

Notes Four Unit Eight Electron Arrangements Forelements

• Compare the atomic models of Rutherford and Bohr. • Describe the quantum mechanical interpretation of electrons in

atoms. • State Pauli's exclusion Principle, the aufbau principle, and

Hund's rule, and describe their roles in determining the electron configuration of atoms.

Atomic ModelRutherford model*Mostly Empty Space

Very Small,Very Dense,Positive Charged,

*Nucleus…

Where were the electrons?What are the electrons doing?

+Quantum Amount

Bohr model

De Broglie’s Wave model for Electrons• Wave Nature

• Different solutions for e-1 actions.

• e-1’s act as a particle or a wave.

• e-1’s absorb or release Quantum Amount of NRG.

• Demo of waves on a string

Standing Waves

S Orbital

X-axis

y-axis

z-axis

p Orbitals Shapes

x-axis

z-axis

y-axis

p Orbitals Assembled

x-axis

z-axis

y-axis

Quantum Model for The Shell of The Atom

Electron Order of FillingAufbau principle fill the lowest energy level first

Orbital Filling Diagram

• Write the orbital filling diagram for Ne.

• How many electrons does Ne have?

• Final Answer

• Short Hand Answer

10 e-1

1s22s22p6

[He]2s22p6

attract

Orbital Filling Diagram

• Write the orbital filling diagram for Na.

• How many electrons does Na have?

• Final Answer

• Short Hand Answer

11 e-1

1s22s22p6

[Ne]3s1

3s1

Orbital Filling Diagram

• Write the orbital filling diagram for Cl.

• How many electrons does Cl have?

• Final Answer

• Short Hand Answer

17 e-1

1s22s22p63s23p5

[Ne]3s23p5

Notes Five Unit Eight

• Electron Dot diagrams • Quantum Numbers

Electron Dot Diagram for Neon

[He]2s22p6

Ne●●

● ●●●

● ●

Electron Dot Diagram for Sodium

[Ne]3s1

Na●

Electron Dot Diagram for Chlorine

[Ne]3s23p5

●●

● ●●●

●Cl

Quantum Numbers• Addresses for electrons

• Four numbers for each address

• No two addresses are the same

First number is n =1 , 2 , 3 , 4 , 5 , 6 , 7 (DistanceFrom the

Nucleus)Second number is l = 0 , 1, 2 , 3s p d f

Third number is ml = 0 = +1, 0, -1 = +2, +1, 0, -1, -2= +3, +2, +1, 0, -1, -2 , -3

p orbitald orbital

f orbitalForth number is ms = +1/2 or -1/2

s orbital

NodalPlane

P orbital Nodal planes (l=0)

X-axis

y-axis

z-axis

?

P orbital Nodal planes (l=1)

x-axis

z-axis

y-axis

x

y

z

Nodal planes (l=2)

n= l= ml = ms =3 2 -2 +1/2

Quantum Numbers

l = 0(s), 1(p), 2(d), 3(f) =

ms = +1/2 or -1/2=

n= l= ml = ms =3 1 0 -1/2

Quantum Numbers

l = 0(s), 1(p), 2(d), 3(f) =

ms = +1/2 or -1/2=

n= l= ml = ms =7 0 0 +1/2

Quantum Numbers

l = 0(s), 1(p), 2(d), 3(f) =

ms = +1/2 or -1/2=

n= ml = ms =4 3 +2 -1/2l=

Quantum Numbers

Quantum Number for Last e-1 in In

n=5 l= 1 ml=+1 ms=+1/2

Many e-1 does In have?49 e-1

Short hand element?KrMany e-1 does Kr have?36 e-1

How many e-1 to account for?13 e-1

Quantum #’s for Last e-1

Short-hand fills to where?Fill-in Valence13 e-1