Section 7.1- The Nature of Light Flashcards
the ____________________ of electrons in atoms is one of the most important concepts in chemistry, for it largely determines the chemical properties of an element
arrangement
can be described as a periodic back and forth motion that transmits energy
wave
the high points of a series of waves are called
crests
the lowest points of a wave are called
troughs
the distance between any two corresponding points on successive waves
wavelength
represents wavelength
lambda (upside down y)
can be considered a measure of the wave’s strength
amplitude
the number of compete waves that pass by a point in a given time
frequency
one wave per second
the SI unit of frequency
hertz
simply the rate at which the wave travels
speed
wavelength, frequency, and speed are mathematically related by this equation
v (wave speed/velocity) = lambda (wavelength) x f (frequency)
some of the first detailed investigations into the behavior of light were made by
Sir Isaac Newton (his book Optiks)
proposed the particle theory of light
Newton
the idea that light can be pictured as streams of tiny particles emitted by light sources
particle theory of light
proposed the wave theory of light
Christiaan Huygens
states that light consists of a series of waves rather than individual particles
wave theory of light
showed that a light wave can be accurately described in terms of an electric field and a magnetic field vibrating at right angles to each other
James Clerk Maxwell
two vibrating fields act together as a single
electromagnetic wave
scientists represent the speed of electromagnetic waves (including light) by the symbol
c
c (speed of light) equals
3.00 x 10^8 m/s
is one of the fundamental constants of the universe
speed of light
the measured speed of ___________ in a vacuum never varies
light
equation for speed of electromagnetic waves including light
c= lambda (wavelength) x f (frequency)
electromagnetic waves require no _____________ to travel through
medium
an arrangement of all forms of electromagnetic radiation in order of frequency and wavelength is the
electromagnetic spectrum
showed that light cannot be classified as simply particles or waves; rather, light has characteristics of both particles and waves
Max Planck and Albert Einstein
the two sided nature of light is known as
wave-particle duality
states that light consists photons
quantum theory of light
tiny bundles or packets of energy
photon
the amount of energy a photon contains is proportional to its _____________
frequency
the quantum theory of energy allows us to define light as
electromagnetic waves traveling as photons
a consequence of quantum theory is that light must consist of
whole number of photons
equation for the energy of a photon
E = hf
Planck’s constant
h
6.63 x 10 ^-34 J x s
