UCI History of Bonding Maps Concept map

We spent the first part of the term exploring theevolution of the atomic model. [Recall that a
scientific model is “a physical and/or mathematical
and/or conceptual representation of a system of
ideas, events, or processes.”] The attached
infographic nicely summarizes each of the models
(see below, and full image on Canvas], their
experimental underpinnings, their strengths and
their shortcomings. These developments in science
are what the philosopher Thomas Khun described
as revolutionary (or “extraordinary’) science, which
is underpinned by major paradoxes and paradigm
shifts.
A HISTORY OF THE ATOM: THEORIES AND MODELS
How have our ideas about atoms changed over the years? This graphic looks at atomic models and how they developed.
SOLID SPHERE MODEL PLUM PUDDING MODEL NUCLEAR MODEL PLANETARY MODEL QUANTUM MODEL
JOHN DALTON
J.J. THOMSON
ERNEST RUTHERFORD
NIELS BOHR
ERWIN SCHRÖDINGER
@ 1803
1904
1911
1913
bd 1926
Do
on the Ancient
Thomson
he called corpusdesin
Rutherford fred poly
charged alpha parties at hin
B modified
o’s
Schvdinge wated that
electrons do not move in
A HISTORY OF THE ATOM: THEORIES AND MODELS
How have our ideas about atoms changed over the years? This graphic looks at atomic models and how they developed.
QUANTUM MODEL
SOLID SPHERE MODEL
PLUM PUDDING MODEL
NUCLEAR MODEL
PLANETARY MODEL
JOHN DALTON
J.J. THOMSON
ERNEST RUTHERFORD
NIELS BOHR
ERWIN SCHRÖDINGER
1803
1904
1911
1913
1926
Dalton drew upon the Ancient
Greek idea of atoms (the word
‘atom’ comes from the Greek
atomos’ meaning indivisible).
His theory stated that a
are indivisible, those of a given
element are identical, and
compounds are combinations of
different types of atoms.
atoms
Thomson discovered electrons
(which he called ‘corpuscles”) in
atoms in 1897, for which he won
a Nobel Prize. He subsequently
produced the ‘plum pudding
model of the atom. It shows the
atom as composed of electrons
scattered throughout a spherical
cloud of positive charge.
Rutherford fired positively
charged alpha particles at a thin
sheet of gold foil. Most passed
through with little deflection, but
some deflected at large angles.
This was only possible if the atom
was mostly empty space, with
the positive charge concentrated
in the centre: the nucleus.
Bohr modified Rutherford’s
model of the atom by stating
that electrons moved around the
nucleus in orbits of fixed sizes
and energies. Electron energy
in this model was quantised;
electrons could not occupy
values of energy between the
fixed energy levels.
Schrödinger stated that
electrons do not move in set
paths around the nucleus, but
in waves. It is impossible to
know the exact location of the
electrons; instead, we have
‘clouds of probability’ called
orbitals, in which we are more
likely to find an electron.
RECOGNISED ATOMS OF A PARTICULAR
ELEMENT DIFFER FROM OTHER ELEMENTS
RECOGNISED ELECTRONS AS
COMPONENTS
OF ATOMS
REALISED POSITIVE CHARGE WAS
LOCALISED IN THE NUCLEUS OF AN ATOM
PROPOSED STABLE ELECTRON ORBITS;
EXPLAINED THE EMISSION SPECTRA OF
SOME ELEMENTS
SHOWS ELECTRONS DON’T MOVE AROUND
THE NUCLEUS IN ORBITS, BUT IN CLOUDS
WHERE THEIR POSITION IS UNCERTAIN
ATOMS AREN’T INDIVISIBLE – THEY’RE
COMPOSED FROM SUBATOMIC PARTICLES
NO NUCLEUS; DIDN’T EXPLAIN LATER
EXPERIMENTAL OBSERVATIONS
DID NOT EXPLAIN WHY ELECTRONS
REMAIN IN ORBIT AROUND THE NUCLEUS
MOVING ELECTRONS SHOULD EMIT ENERGY
AND COLLAPSE INTO THE NUCLEUS, MODEL
DID NOT WORK WELL FOR HEAVIER ATOMS
STILL WIDELY ACCEPTED AS THE MOST
ACCURATE MODEL OF THE ATOM
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This graphic
Use the atom infographic as an example to follow,
and on a page draw by hand an infographic of
bonding theories, from Lewis to Valence Bond and
Molecular Orbital Theory. Use two different
diatomic molecules (such as N2, O2, or F2) to
illustrate how the models provide an increasing
level of detail and complexity as they are applied to
your examples. ie. You should show how the
bonding description changes from Lewis to
Valence Bond to Molecular Orbital theories. What
are the benefits and shortcomings of each model?
Here is your Infographic checklist:
.
.
General description of bonding;
Brief description of each bonding theory;
For each bonding theory:
• 2 fully developed bonding examples (*with
appropriate labels and other descriptions)
Benefits of the bonding theory
Shortcomings of the bonding theory
.
.
Here is your Infographic checklist:
.
General description of bonding;
Brief description of each bonding theory;
For each bonding theory:
• 2 fully developed bonding examples (*with
appropriate labels and other descriptions)
Benefits of the bonding theory
Shortcomings of the bonding theory
Please reference all resources that you used in
developing your infographic.
Grading: 2 pt for general description of bonding; 5
pts for each Model (description, two examples,
benefits and shortcomings/challenges)