Download Ch#1 Introduction - Seattle Central College

Chemistry 121
Introduction
What is Chemistry
Chemistry is the study of matter and its changes
What is Matter?
Matter is anything that occupies space and has
weight.
Examples of Matter
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Pens and pencils
Paper
Students
Desks
Cars
Airplanes
Is Air Matter?
Air would be matter if it takes up space and has
weight.
Is Air Matter?
Air would be matter if it takes up space and has
weight.
Does it?
Is Air Matter?
Air would be matter if it takes up space and has
weight.
Does it?
The space that air takes up is called the
atmosphere.
Does air have weight?
Is Air Matter?
Air would be matter if it takes up space and has
weight.
Does it?
The space that air takes up is called the
atmosphere.
Does air have weight?
Yes air does have weight, if not, then it would
flow into outer space.
Is Air Matter?
Air would be matter if it takes up space and has
weight.
Does it?
The space that air takes up is called the
atmosphere.
Does air have weight?
Yes air does have weight, if not, then it would
flow into outer space. One liter of air weighs
1.29 grams.
What are Changes?
In the study of chemistry we talk about two
different kinds of changes, physical and chemical
What are Changes?
In the study of chemistry we talk about two
different kinds of changes, physical and chemical
Physical change is a change to matter so that the
identity is not altered; i.e. taste, smell….
What are Changes?
In the study of chemistry we talk about two
different kinds of changes, physical and chemical
Physical change is a change to matter so that the
identity is not altered; i.e. taste, smell….
Chemical change is a change to matter so that its
identity is changed; i.e. different smell, color, taste.
Examples of Physical Change
• Tearing paper; starts out paper and ends as paper
• Folding paper ; starts out paper and ends as
paper
• Melting of ice ; starts out water and ends as
water
• Evaporation of water ; starts out water and ends
as water
Examples of Chemical Change
• Wood burning; starts out as wood ends up as
smoke and ashes, different smell and taste,
right?
• Steel rusting; starts out as steel ends up as
rust, different smell and taste
• Healing of a wound; starts out a blood ends
up as scar tissue, different color, taste and
smell
Matter Continued
Is everything matter?
Matter Continued
Is everything matter? No, not everything we
can think of has weight and takes up space.
Matter Continued
Is everything matter? No, not everything we
can think of has weight and takes up space.
For example personality!
Matter Continued
Is everything matter? No, not everything we
can think of has weight and takes up space.
For example personality! One might argue that
personality takes up the space of ones brain or
person, but…
Matter Continued
Is everything matter? No, not everything we
can think of has weight and takes up space.
For example personality! One might argue that
personality takes up the space of ones brain or
person, but…not all personable people are
overweight. Thus personality does not have
weight, and is therefore not matter.
Matter Continued
How about thought? Again we might argue that
thought takes up the space of ones brain and
your mother told you about heavy thoughts,
but….
Matter Continued
How about thought? Again we might argue that
thought takes up the space of ones brain and
your mother told you about heavy thoughts,
but….If you get on the bathroom scale and start
having heavy thoughts, your weight does not go
up!
Matter Continued
How about thought? Again we might argue that
thought takes up the space of ones brain and
your mother told you about heavy thoughts,
but….If you get on the bathroom scale and start
having heavy thoughts, your weight does not go
up! That means thought is not matter, so if
someone studies thought, they are not doing
chemistry.
Examples of Chemistry
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The study of why wood burns
The study of why cement does not burn
The study of why nails rust
The study of milk spoiling
These all fit the definition of chemistry since
they deal with change and matter
History of Chemistry
Who were the first chemists?
History of Chemistry
Who were the first chemists?
History of Chemistry
Who were the first chemists?
Cavemen
History of Chemistry
What kind of matter and changes did the
cavemen study?
History of Chemistry
What kind of matter and changes did the
cavemen study? Fire and food!
Archeologists have found evidence of fire in
caves and animal bones too. Cooking meat
makes meat chewable. Chewing raw meet
wears out ones jaw.
History of Chemistry
The next group that left archeological evidence
of chemistry were the Egyptians. Their
chemistry involved mummies, textile dyes, ink,
paper and paints most of which can be found
inside the pyramids.
History of Chemistry
The first group of people to leave written
records of their chemistry were the Greeks.
From Greek writings, we can see that the Greeks
made observations, and created reasons for
these observations, called hypothesis. They did
not attempt to prove their hypothesis by
experimentation, thus their chemistry efforts
were philosophical in nature as opposed to
science in nature.
History of Chemistry
The first group of chemists to test hypothesis
with experiments were the alchemists.
Alchemists were a group of Europeans that
were trying to change matter in to different
kinds of matter. For example, they were trying
to change lead into gold. The major results of
their experiments were to prove most of the
Greek ideas of chemistry to be false and to show
a clear distinction between science and
philosophy.
History of Chemistry
A major short coming of the Alchemists
chemistry was irreproducible results, caused by
lack of measurement understanding. For
example, on day 1 mixing two kinds of matter
produced black matter, while doing the same
thing the next day produced red matter. The
Alchemists were the first group of chemists to
make observations, create hypothesis, and to
test their hypothesis with experiments.
Modern Chemistry
Antoine Lavoisier was the founder of modern
chemistry by making careful measurements.
Modern Chemistry
Lavoisier’s careful measurements now made
experiments reproducible. Chemists in other
countries could now do the same experiment
and get the same results. This now allowed
chemists to prove a hypothesis to be correct by
experimentation, thus leading to the discovery
of theories and laws.
Modern Chemistry
Lavoisier’s Theories and Laws
• Law of Conservation of Mass
• Atomic Theory
Classification of Matter
Matter
Homogeneous
Substance
Element
Heterogeneous
Solution
Compound
Classification of Matter
Homogeneous and Heterogeneous
Homogeneous matter looks the same
everywhere with a microscope, but since we
lack microscopes we will use our eyes and not
our imagination. Heterogeneous matter does
not look the same everywhere.
Classification of Matter
Homogeneous or Heterogeneous?
Wood
Carpet
Margarine
Gold
Classification of Matter
Homogeneous or Heterogeneous?
Wood
Heterogeneous
Carpet
Margarine
Gold
Classification of Matter
Homogeneous or Heterogeneous?
Wood
Carpet
Heterogeneous Heterogeneous
Margarine
Gold
Classification of Matter
Homogeneous or Heterogeneous?
Wood
Carpet
Heterogeneous Heterogeneous
Margarine
Homogeneous
Gold
Classification of Matter
Homogeneous or Heterogeneous?
Wood
Carpet
Heterogeneous Heterogeneous
Margarine
Gold
Homogeneous Homogeneous
Classification of Matter
Solution is a homogeneous random combination of
two or more different types of matter.
For example a random amount of salt and water
combined together produces a homogeneous
mixture, called salt water. Random combination
means some salt and some water.
Classification of Matter
Any combination the produces a homogeneous
result that is not randomly created is called a
substance.
For example, combining two hydrogen atoms and
one oxygen atom produces a compound of water,
which is a substance. Or the combination of two
oxygen atoms, gives a molecule of oxygen.
Classification of Matter
Homogeneous matter created by the same atom
is called and element. Exact combinations of
different elements is called a compound.
Classification of Matter
Label the following examples of matter as
heterogeneous, solution, compound or element.
• Sand
• Sea water
• Tap water
• Steel
• Antimony
• Air
• Distilled water
• Cement
• Wine
Classification of Matter
Label the following examples of matter as
heterogeneous, solution, compound or element.
• Sand-Heterogeneous
• Sea water
• Tap water
• Steel
• Antimony
• Air
• Distilled water
• Cement
• Wine
Classification of Matter
Label the following examples of matter as
heterogeneous, solution, compound or element.
• Sand-Heterogeneous
• Sea water-Heterogeneous
• Tap water
• Steel
• Antimony
• Air
• Distilled water
• Cement
• Wine
Classification of Matter
Label the following examples of matter as
heterogeneous, solution, compound or element.
• Sand-Heterogeneous
• Sea water-Heterogeneous
• Tap water-Solution
• Steel
• Antimony
• Air
• Distilled water
• Cement
• Wine
Classification of Matter
Label the following examples of matter as
heterogeneous, solution, compound or element.
• Sand-Heterogeneous
• Sea water-Heterogeneous
• Tap water-Solution
• Steel-Solution
• Antimony
• Air
• Distilled water
• Cement
• Wine
Classification of Matter
Label the following examples of matter as
heterogeneous, solution, compound or element.
• Sand-Heterogeneous
• Sea water-Heterogeneous
• Tap water-Solution
• Steel-Solution
• Antimony-Element
• Air
• Distilled water
• Cement
• Wine
Classification of Matter
Label the following examples of matter as
heterogeneous, solution, compound or element.
• Sand-Heterogeneous
• Sea water-Heterogeneous
• Tap water-Solution
• Steel-Solution
• Antimony-Element
• Air-Solution
• Distilled water
• Cement
• Wine
Classification of Matter
Label the following examples of matter as
heterogeneous, solution, compound or element.
• Sand-Heterogeneous
• Sea water-Heterogeneous
• Tap water-Solution
• Steel-Solution
• Antimony-Element
• Air-Solution
• Distilled water-Compound
• Cement
• Wine
Classification of Matter
Label the following examples of matter as
heterogeneous, solution, compound or element.
• Sand-Heterogeneous
• Sea water-Heterogeneous
• Tap water-Solution
• Steel-Solution
• Antimony-Element
• Air-Solution
• Distilled water-Compound
• Cement-Heterogeneous
• Wine
Classification of Matter
Label the following examples of matter as
heterogeneous, solution, compound or element.
• Sand-Heterogeneous
• Sea water-Heterogeneous
• Tap water-Solution
• Steel-Solution
• Antimony-Element
• Air-Solution
• Distilled water-Compound
• Cement-Heterogeneous
• Wine-Solution
The End
Chapter #1