Transcript Chemistry Chapter 5 - Manistique Area Schools

Chemistry
Chapter 5
Ch5 Notes #1
Light and Quantized
Energy
• An element’s chemical behavior is
connected to electron arrangement
• Electron arrangement and chemical
properties are connected to light
energy
• Form of energy that exhibits wave- like
behavior….
• Ex. Visible light, x-rays, microwaves,
etc….
• EM Spectrum – all electromagnetic
radiation
Waves
• Described by:
• Wavelength: Shortest distance
between 2 equivalent points on a
continuous wave
• Amplitude: height from origin to crest
• Frequency: how many complete waves
pass a point in a given amount of time
• Hertz; waves per second
• Speed of light (c)- wavelength x speed
• 3.00 x 108 m/s
Waves - review
Light – Wave or particle?
• Max Planck
• Quantum – minimum amount of
energy that can be gained or lost
by an atom…
• Albert Einstein (1905)
• Completion of the particle model
• EM radiation = stream of tiny particles
(bundles of energy) that move like a
wave – called photons
• Photon = a particle of EM radiation with
no mass that carries a quantum of
energy
Light – Wave or particle?
• EM radiation – wave and particle
like!!
Increasing Energy
Atomic Emission Spectra
• Set of frequencies of the electromagnetic
waves emitted by atoms of an element
• Each element gives off a unique set of
frequencies
• Quantum Mechanics
• Electrons emit certain energy (related to
wavelength)
• Each spectra consists of several “lines” of
color…not a continuous range like a visible
spectra (rainbow) – there are “black”
spaces in between the colors.
Example
Real Life Uses
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Fireworks
Neon Signs
Bon-Fire (Old Christmas lights)
Rainbows
Scientists can learn what stars are
made of by observing the spectrum
they emit
• Photoelectric panels (solar houses,
calculators)