chapter 1, section 1.1, 1.2, 1.3
TRANSCRIPT
-
8/9/2019 Chapter 1, Section 1.1, 1.2, 1.3
1/12
Introduction to
Chemistry
Lorena Ma. Wheelock Gtz.
1.1 The Stories of Two Chemicals.
1.2 Chemistry and Matter.1.3 Scientific Methods.
-
8/9/2019 Chapter 1, Section 1.1, 1.2, 1.3
2/12
1.1 The Stories of Two ChemicalsThe Ozone Layer
Ozone (O): is a chemical that absorbs radiation
before ot reaches Earth.Is located in the stratosphere, this
layer is above the troposphere. It
extends from 15-50 km. above the
Earths surface.
Stratosphere
Living things can e
xist onEarth because of
OZONE
Where does the ozonelayer is located?
-
8/9/2019 Chapter 1, Section 1.1, 1.2, 1.3
3/12
The Ozone Layer
Radiation from
sun causes
oxygen to break
into two identicalparticles of
oxygen. These
individual oxygen
particlescombine with
oxygen gas to
form ozone,
How ozone forms?
which consists of three oxygen particles.
-
8/9/2019 Chapter 1, Section 1.1, 1.2, 1.3
4/12
The Ozone Layer
InformationIt was 1st. Identified and
measured in the late 1800s
Ozone forms over theEquator where the rays
of sunlight are
strongest and the flow
toward the poles.
G. M. B. Dobson
began to measure
the amount of
ozone in the
atmosphere, more
than 300 D.U.
(Dobsons Units)
1800
1900
1920
1981-1983
1985
A research group from
British Antarctic
Survey was
monitoring the
atmosphere above the
Antarctica. They werelow levels of ozone
less than 160 D.U.
In Octoberwas confirmed
the decrease
of the amount
of ozone, and
that the ozonelayer was
thinning.
-
8/9/2019 Chapter 1, Section 1.1, 1.2, 1.3
5/12
1.1 The Stories of Two ChemicalsChlorofluorocarbons (CFCs)
Is a chemical that contains:chlorine, fluorine and
carbon. At 1935 refrigerators and ser air-conditionersused CFCs as coolants.
Scientists 1st. began to notice the presence
of CFCs on the atmosphere in the 1970s.
Two separate occurrences had been
noticed and measured: the protective ozone layer
was thinning and increasing large quantities of
CFCs were drifting into the atmosphere.
-
8/9/2019 Chapter 1, Section 1.1, 1.2, 1.3
6/12
1.2 Chemistry and MatterChemistry: The Central of Science.
Chemistry: is the study of matter and the change
that undergoes. Is the central of our everyday lives.
Is important because some food and clothes had
pass through a chemical process.
Why do
es the chemistry
is so important?
-
8/9/2019 Chapter 1, Section 1.1, 1.2, 1.3
7/12
Matter: is anything that has mass and takes up
space.
1.2 Chemistry and MatterMatter and its Characteristics:
Mass: is a measurement that
reflect the amount of matter.
Thoughts and ideas are not matter.
Is everything made up ofmatter?
-
8/9/2019 Chapter 1, Section 1.1, 1.2, 1.3
8/12
Matter and its Characteristics:
Mass andWeightWeight: is a measure for the amount on matter
but also of the Earths gravitational energy effect.
Scientist could identify the gravitational force
every time they weigh something, but that wasnt
practical. This is why they use mass as a way to measure
matter independently of the gravitational force.
-
8/9/2019 Chapter 1, Section 1.1, 1.2, 1.3
9/12
1.2 Chemistry and MatterChemistry Branches
Chemistry
Analytical
ChemistryPhysical
Chemistry
Inorganic
Chemistry
Organic
Chemistry
Biochemistry
-
8/9/2019 Chapter 1, Section 1.1, 1.2, 1.3
10/12
1.3 Scientific MethodsA Systematic Approach:
Scientific Method: is a systematic approach used
in scientific study. It is an organized process used by
scientists to do research, an it provides a method forscientists to verify the work of others.
Steps:
*Observation
*Hypothesis*Experiments
*Conclusion
*Theory
*Scientific Law
-
8/9/2019 Chapter 1, Section 1.1, 1.2, 1.3
11/12
A Systematic Approach:Steps
*Observation: is the act of gathering information,types of observation that scientists first make are
qualitative data (color, odor, shape, etc.) in chemistry it
is: temperature, pressure, volume, etc.
*Hypothesis: is a tentative explanation for whathas been observed. Is stated what they believe to be
happening, a data to support.*Experiments: is a set of controlled observations
that test the hypothesis, the results can be:independentvariable: temperature,dependent variable:value
change in response to change the independent
variable. And experiment have a valuable control, a
standard comparison.
-
8/9/2019 Chapter 1, Section 1.1, 1.2, 1.3
12/12
A Systematic Approach:Steps
*Conclusion: is a judgment based on theinformation obtained. The hypothesis can never be
true you just gave the affirmation that maybe it can be
true.*Theory: is an explanation that has been
supported by many, many experiments. States a broad
principle of nature that has been supported over time.
It lead to new conclusions.
*Scientific Law: is a relationship in nature thatsupported by many experiments, it is up to scientists
to develop further hypotheses and experiments to
explain why this relationship exist.