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Week 5 CHEM 1310 - Sections L and M 1

Exam 1 Results

4 Perfect Scores! Average = 67

12% 14%

22% 23%

27%

2%

Week 5 CHEM 1310 - Sections L and M 2

Exam 1 Score

Look up Score– Via WebCT: One point already added to

ScanTron™ score!– Via Lecture Notes Link: Correct Score Listed

Papers returned in lab this Fri

Week 5 CHEM 1310 - Sections L and M 3

Content Recap

ATOMS

MOLECULES IONS

BondingBonding

States of Matter

Gases, Liquids, Solids

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Week 5 CHEM 1310 - Sections L and M 4

Content Recap

ATOMS

MOLECULES IONS

BondingBonding

How do moleculesinteract with each

other to form liquidsand solids?

Quantum Mechanics

How does bondingoccur on the

molecular level?

Week 5 CHEM 1310 - Sections L and M 5

Mon| Sep 17, 2007

Chapter 12: Quantum Mechanics & AtomicTheory– 12.1 Electromagnetic Radiation– 12.2 The Nature of Matter– 12.3 The Atomic Spectrum of Hydrogen– 12.4 The Bohr Model– 12.5 Quantum Mechanical Description of an Atom– 12.6 SKIP THIS SECTION

What is quantum mechanics?Why study electromagnetic radiation to understand it?

Week 5 CHEM 1310 - Sections L and M 6

What is Quantum Mechanics?

Scanning Tunneling Microscopy1986 Nobel Prize in Physics

Classical Mechanics

F = m x a

Only applies to“big” objects!

Quantum mechanics is a field of study that describes the motion of “small” objects (i.e. subatomic particles).

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Week 5 CHEM 1310 - Sections L and M 7

What is Quantum Mechanics?

Bonding– Occurs through movement in electrons– Must understand how electrons move

Quantum Mechanics– Small objects (such as light and electrons) move

according to rules of quantum physics– “Quantum” = small packet of radiation that exhibits a

discrete amount of energy

How can we describe quanta, or radiation?

Week 5 CHEM 1310 - Sections L and M 8

Electromagnetic Radiation

Forms of Energy– Kinetic

– Potential

Modes of Energy Transfer– Light (or Radiation)– Heat (Enthalpy - Chapter 9)

Week 5 CHEM 1310 - Sections L and M 9

2 Views of Light

Frequency vs. Wavelength

Amplitude

Amplitude

Time, s

λ, nm

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Week 5 CHEM 1310 - Sections L and M 10

Electromagnetic Radiation

λ ν = c λ = “lambda”ν = “nu” = frequency

Week 5 CHEM 1310 - Sections L and M 11

Frequency

λ ν = c

Units of Frequencycycles/sec = hertz

Notice how λ changes with ν

Week 5 CHEM 1310 - Sections L and M 12

Electromagnetic Spectrum

V - I - B - G - Y - O - R

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Week 5 CHEM 1310 - Sections L and M 13

Dual Nature of Quantum Matter

Dual nature of light: wave and particulate nature of EM radiation

Ephoton = h ν =h cλ