Download 6 - The Quantum Atomic Model SCH4U – Structure and Properties of

SCH4U – Structure and Properties of Matter
582715435
Date: ________________________
The Quantum Atomic Model
Niels Bohr
Bohr saw atomic spectra as evidence that the energy of electrons in an atom is
“___________________” (limited to only certain __________________________)
Bohr introduced the first “_________________ model” the atom by concluding that
electrons in an atom are confided to discrete “___________________________”
The energies that electrons can possess are determined by the allowable
_______________________ in the atom
In unenergized atoms, electrons would be found in their lowest possible energy
levels, known as their “_______________________________”
Bohr’s Model of the Atom
All electrons have their __________________ at a certain distance from the nucleus
Electrons exist in an orbit, but not in __________________ the levels
Explained the line spectrum of ____________________
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SCH4U – Structure and Properties of Matter
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Bohr’s Explanation of Atomic Spectra
When energized, electrons can be “_________________” to higher energy levels
Electron promotion requires that the electron gain the _______________ amount of
energy required to make the ________________ from one allowable level to another
The amount of energy required for a transition is equal to the energy ____________
between the two levels involved
Bohr concluded that the “missing frequencies” of light in a dark line spectrum
correspond to the specific _________________________ that will excite an electron
from one lower level to another higher level
The frequency of light = the ____________________ in _______________ (ΔE)
between the two levels
“_________________” electrons will eventually return to lower energy levels by
_____________________
This energy is released as a photon of light of a specific frequency (_____________)
The frequency of light emitted corresponds to the energy difference (ΔE) between
the two energy levels involved in the electron transition
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SCH4U – Structure and Properties of Matter
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These frequencies of light would be visible as the distinct bands of light in the bright
line spectrum
Atomic spectra show these distinct bands of light because electrons cannot exist
_____________________________________ and transitions between levels are
_________________________
Bohr developed a _______________________ model of the hydrogen atom based
on these ideas
He developed an equation that allowed him to determine the energy of an electron in
any energy level, n
Knowing the energy of an electron in any energy level allowed Bohr to determine the
________________________ between any two levels
Using Planck’s equation, Bohr was able to develop an equation that would allow him
to _____________________________ of light in the hydrogen spectrum
Bohr’s model not only successfully predicted the colours of light produced by
hydrogen atoms in the visible region (________________ series) but also those that
are produced in the infra-red region (_______________ series) and the ultra-violet
region (______________ series)
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SCH4U – Structure and Properties of Matter
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Louis de Broglie
de Broglie reasoned that if light has both _______________ and _______________
properties, then maybe particles also have _________ properties
He considered the two equations defining energy:
Using this equation, de Broglie was able to determine the wavelength of any moving
particle given its _______________________ and ______________________
Applying this idea to the atom, de Broglie proposed that an electron behaves like a
____________________________ bound to the nucleus
To explain the _____________________ of an electron de Broglie proposed that the
___________________ of the electron must fit the circumference of its orbit exactly,
resulting in only a defined number of _____________________________________
Werner Heisenberg
Heisenberg (1927) showed that due to the dual nature of matter, it is impossible to
know simultaneously with exact precision, the ____________ and ______________
of a particle
This became known as the “Heisenberg Uncertainty Principle”
Applying this to the structure of the atom, it is impossible to know with any degree of
certainty ________________ or ______________ an electron moves in an atom
The act of determining the where an electron is disturbs the electron
According to Heisenberg’s calculations, the uncertainty in the position of an electron
in an atom is about the size of the atom itself!
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SCH4U – Structure and Properties of Matter
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Erwin Schrödinger
Schrödinger used conventional wave equations to develop a __________________
__________________________________________________________________
The solutions to this equation provides us with what is called the electron’s “_______
_________________” (Ψ) which defines the ______________ of finding an electron
in any given location around the nucleus
This ________________________ of finding an electron is called an ____________
These equations assigned an electron a set of three _________________________
that defined an electron’s energy level, sublevel and orbital
Max Born
Used Schrödinger’s equations to develop _________________________ that could
produce a plot of __________________________ which define a _______________
____________________ in space around the nucleus where there is a 90%
probability of finding an electron represents the electron’s ______________
Wolfgang Pauli
Pauli proposed a fourth quantum number with _____ possible values to resolve
inconsistencies between observed spectra and the developing theory of quantum
mechanics
The fourth quantum number relates to a property of the electron called _________
which is responsible for an electron’s weak _______________________
He formulated the “Pauli Exclusion Principle”, which stated that no two electrons
could exist in the _______________________________
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SCH4U – Structure and Properties of Matter
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Paul Dirac
Dirac developed a new version of the wave equation that included the fourth
quantum number for ______________________
An electron can have one of two possible spins (“______” or “_________”), resulting
in two opposing magnetic fields
Electrons with opposite ________ would have opposite _______________________
which would minimize ___________________ allowing these electrons to share the
same region in space or _______________
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