Transcript Developing Ideas about Matter

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Heating and Freezing food temporarily
sterilizes the food, meaning the microorganisms are killed.
Salting is used to preserve meat and fish, by
drawing the moisture out of the meat,
killing the micro-organisms or leaving them
inactive.
Fermentation is a biochemical food
preserving technique involving the bacteria
lactobacilli. They are present on all living
things, and convert sugars and starches to
lactic acid. Lactic acid is a preservative that
prevents growth of bacteria.
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Metallurgy is the science of
producing and using metals.
Copper was one of the earliest
metals produced, and a
process called "annealing"
enhanced the qualities of the copper.
Annealing is the process of heating copper,
the result is that a much stronger tool can
be created.
"Smelting" is the process of heating copper
ore to high temperatures to drive out any
impurities in the metal and be left with pure
copper
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The philosopher
Aristotle believed
that there were only
4 types of matter:
Earth, Air, Fire, and
Water.
This belief
continued
for 2000
years.
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This was a combination of
chemistry and magic.
Usually alchemy is
described as parlour tricks,
and most people studied
alchemy with the hopes of
turning lead into gold.
Alchemists where the first
group to begin to question
Aristotle's notion of the four
states of matter.
At this time the idea of the
"atom" began to be debated
among alchemists.
John Dalton
“billiard ball” model or “solid sphere” model
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Model: billiard ball model or solid sphere
model
◦ The atom is the smallest particle of matter
◦ For a given substance, atoms are identical in size,
shape and mass
◦ Smallest part of an element that can take part in
chemical change and combined in whole numbers
◦ Atom is indivisible, unchangeable and
indestructible
J.J. Thompson
“plum pudding” model
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Model: plum pudding model
◦ The atom is a solid bulk of positive charge in which
negative charges are dispersed throughout.
Ernest Rutherford
Nuclear Model
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Model: “nuclear” model
◦ the positive charges and mass of the atom is
concentrated in the center of the atom or the
nucleus
◦ The negatively charged particles are moving rapidly
around the nucleus
Neils Bohr
Bohr model
“satellite” or “solar system” model
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Electrons are arranged in definite energy
levels (shells)
Electrons follow a prescribed orbit around the
nucleus
Electrons may be dislodged from orbits
(energy levels) when they absorb or release
energy.
Erwin Schrodinger
Wave mechanical
model or
Electron cloud model
Louis de Broglie
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Model: Electron Cloud Model
◦ Electron has wave-like properties
◦ Electrons exist in definite energy levels
◦ Location of the electron is uncertain, described as
being found in a certain region of space around the
nucleus
◦ Theses regions of space are called the cloud
Homework:
1. Read Science 10 p. 18 -25
2. complete Check and Reflect # 1-8, due next day.