chapter 1 - introduction to chemistry objectives define chemistry differentiate between the 5...
TRANSCRIPT
Objectives
Define Chemistry Differentiate between the 5 branches of
Chemistry Apply the general plan in solving chemistry
word problems
SECTIONS
1.1 Chemistry 1.2 Chemistry Far and Wide 1.3 Thinking Like a Scientist 1.4 Problem Solving in Chemistry
1.1 Chemistry
Matter – anything that takes up space and has mass
Chemistry – the study of matter and the changes that matter undergoes
Organic Chemistry – the study of all chemicals that contain carbon
Inorganic Chemistry – the study of chemical that do not contain carbon
Biochemistry – the study of processes that take place in organisms
Analytical Chemistry – the study of composition of matter
Physical Chemistry – the area that deals with the mechanism, the rate and the energy transfer that occurs when matter undergoes a change
Pure Chemistry - the pursuit of chemical knowledge for its own sake
Applied Chemistry – research that is directed toward a practical goal or application
Technology – a system of tools, mechanisms, methods to solve a problem, improve a problem or change a problem
Vocabulary-Matter -Chemistry-Organic chemistry-Inorganic Chemistry-Biochemistry -Analytical Chemistry-Physical Chemistry-Pure Chemistry-Applied Chemistry-Technology
Video – What is Chemistry?
Mass vs Weight
Mass: a measure of the amount of matter that an object contains. (SI unit kilogram, kg)
Weight: The force with which the earth pulls on an object. (SI unit Newton, N)
Science and Technology
Science Pure Does not necessarily have an application.
Technology Applied Has practical applications in society. Engineering.
1.2 Chemistry Far and Wide Macroscopic – objects are seen without a microscope
Microscopic - objects that cannot be seen without microscope
Biotechnology – an applied science that uses techniques to produce or process different things
Pollutant - a material found in air, soil or water that hurts living things
Vocabulary- Macroscopic- Microscopic- Biotechnology- Pollutant
Nature of Energy
Energy is involved when:
a bird flies. a bomb explodes. rain falls from the sky.
electricity flows in a wire.
Production of Energy
Hydroelectric plants use running water to generate electricity, however they may flood nearby lands and can disrupt the normal flow of water, both of which negatively affect the environment.
Wind power is increasingly being used as a clean source of renewable energy.
Turbines harvest wind on wind farms and generate electricity.
Solar power is a promising, renewable energy resource than can be turned into electricity, and it is used in many toys and even home heating.
Many other alternative energy sources like geothermal power, which draws upon the earth’s natural heat, and biomass, which produces an alternative to gasoline, are being considered in the movement away from fossil fuel dependence.
Conservation of Energy
In our everyday lives, we can also work to conserve energy.
Insulating, turning off lights and only using appliances like dishwashers when they are full are just some of the ways people can limit energy use in their homes.
Also, carpooling, bicycling, and taking public transportation are effective energy-saving ideas.
What is Biotechnology?
Biotechnology is the manipulation of living organisms and organic material to serve human needs.
Examples: Yeast in bread making and alcohol production Use of beneficial bacteria (penicillin) to kill harmful
organisms Cloning of plants and animals Artificial insemination
1750 B.C.
Origins of “biotechnology” emerge in methods of food production and plant and animal breeding Use of bacteria to produce cheese (food preservation)
Use of natural enzymes in yogurt Use of yeast to produce bread Use of fermentation for producing wine and beer
Biotechnology Industry
Focuses on a variety of research areas including: Health/medicine Food science Environmental science Agriscience
1.3 Thinking Like a Scientist
Scientific Method - a logical approach to the solution of a scientific problem
Observation – the use of senses to obtain an information
Hypothesis – an educated guess
Experiment – a procedure used to verify the hypothesis
Manipulated variable – the variable that you change during an experiment
Responding variable – the variable that is observed during the experiment
Theory - a well tested explanation for a broad set of observations
Scientific Law – a concise statement that summarizes the results of many observations and experiments
Vocabulary-Scientific Method-Observation-Hypothesis-Experiment-Manipulated variable-Responding variable-Theory-Scientific law
Steps of the Scientific Method
1. Problem/QuestionProblem/Question: Develop a question or problem that can be
solved through experimentation.
Steps of the Scientific Method
3. Formulate a HypothesisFormulate a Hypothesis: Predict a possible answer
to the problem or question.Example: If soil
temperatures rise, then plant growth will increase.
Steps of the Scientific Method
4. ExperimentExperiment: Develop and follow a procedure.Include a detailed
materials list.The outcome must be
measurable (quantifiable).
Steps of the Scientific Method
5. Collect and Analyze Collect and Analyze ResultsResults: Modify the procedure if needed.
Confirm the results by retesting.
Include tables, graphs, and photographs.
Steps of the Scientific Method
6. ConclusionConclusion: Include a statement that accepts
or rejects the hypothesis.
Make recommendations for further study and
possible improvements to the procedure.
Steps of the Scientific Method
7. Communicate the Communicate the ResultsResults: Be prepared
to present the project to an audience.
Expect questions from the audience.
Problem/Question
John wonders if the amount of sugar used in the recipe will affect the size of the bread
loaf?
Caution!Be careful how you use
effect and affect.Effect is usually a noun and
affect, a verb.“ The effect of sugar amounts on the rising of
bread.”“How does sugar affect the
rising of bread?”
Observation/Research
John researches the areas of baking and fermentation and tries to come up with a way
to test his question.
He keeps all of his information on this topic in a journal.
John talks with his teacher and she gives him an Experimental Design
Diagram to help him set up his investigation.
Formulate a Hypothesis
After talking with his teacher and
conducting further research, he comes
up with a hypothesis.
“If more sugar is added, then the bread will rise
higher.”
Hypothesis The hypothesis is an
educated guess about the relationship between the independent and dependent
variables.Note: These variables will be defined in the next few
slides.
Independent Variable
The independent, or
manipulated variable, is a factor that’s intentionally varied by the experimenter.John is going to use 25g., 50g., 100g., 250g., 500g. of
sugar in his experiment.
Dependent Variable
The dependent, or responding variable, is the factor that may change as a result of
changes made in the independent variable.
In this case, it would be the size of the loaf of bread.
Experiment
His teacher helps him come up with a procedure and list
of needed materials.
She discusses with John how to determine the control
group.
Control Group
In a scientific experiment, the control is the group that
serves as the standard of comparison.
The control group may be a “no treatment" or an
“experimenter selected” group.
Control Group
The control group is exposed to the same conditions as the experimental group, except for the variable
being tested.All experiments should have
a control group.
Control Group
Because his grandmother always used 50g. of sugar in her recipe, John is going to use that amount in his
control group.
Constants
John’s teacher reminds him to keep all other factors the same so that any observed changes in the bread can be
attributed to the variation in the amount of sugar.
Constants
The constants in
an experiment are all the
factors that the experimenter
attempts to keep the same.
Constants
They might include:Other ingredients to the bread
recipe, oven used, rise time, brand of ingredients, cooking
time, type of pan used, air temperature and humidity where
the bread was rising, oven temperature, age of the yeast…
Experiment
John writes out his procedure for his experiment along with a materials
list in his journal. He has both of these
checked by his teacher where she checks for any
safety concerns.
Trials
Trials refer to replicate groups
that are exposed to the same conditions in an experiment.
John is going to test each sugar variable
3 times.
Collect and Analyze Results
John comes up with a table he can use
to record his data.
John gets all his materials together and carries out his experiment.
Size of Baked Bread (LxWxH) cm3
Amt. of Sugar (g.)
1 2 3 AverageAverage
Size (cmSize (cm33))
25 768 744 761 758
50 1296 1188 1296 1260
100 1188 1080 1080 1116
250 672 576 588 612
500 432 504 360 432
Size of Bread Loaf Size of Bread Loaf (cm(cm33))
TrialsTrials
Control group
Collect and Analyze Results
John examines his data and notices that his control worked the best in this experiment, but not significantly
better than 100g. of sugar.
Conclusion
John rejects his hypothesis, but decides to re-
test using sugar amounts between 50g. and 100g.
Experiment
Once again, John gathers his materials and carries out his experiment.
Here are the results.
Size of Baked Bread (LxWxH) cm3
Amt. of Sugar (g.)
1 2 3 AverageAverage
Size (cmSize (cm33))
50 1296 1440 1296 1344
60 1404 1296 1440 1380
70 1638 1638 1560 1612
80 1404 1296 1296 1332
90 1080 1200 972 1084
Size of Bread Loaf Size of Bread Loaf (cm(cm33))
TrialsTrials
Control group
Communicate the Results
John tells his grandmother about his findings and
prepares to present his project in
Science class.
Alchemists (~300BC-1650 AD)China, India, Arabia, Europe, Egypt
•Aiming to:
Change common metals to gold.Develop medicines.
•Developed lab equipment.
•Mystical.
Theory
A well tested explanation for a broad set of observations.
May use models. May allow predictions. Theories may change to explain new observations.
Law
A statement that summarizes results of observations, but does not explain them.
Changes or is abandoned when contradicted by new experiments.
“No number of experiments can prove me right;
a single experiment can prove me wrong.”
Albert Einstein
Why Study Chemistry - 3 Main Reasons
1.) Understand the Natural World
2.) Career Preparation
3.) Becoming an informed citizen
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.
Why Study Chemistry?
Explaining the Natural World
why cut apples turn brown upon exposure to air.
why the texture of eggs changes from runny to firm as eggs are boiled.
why water expands as it freezes.
why sugar dissolves faster in hot water than in cold water.
why yeast makes bread dough rise.
Satisfy your curiosity…
Why Study Chemistry? Preparing for a
Career•Doctor•Nursing•Firefighter•Turf Management•Geothermal Specialist•Engineering•Artist•Chef•Mechanic•Painters•Farmer•Law Enforcement•Professional Hunter•Physical Therapist
Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved.
You do not need to have the word chemist in your job title to benefit from understanding chemistry.
Assignments Watch the PPT at least 2 times or read the textbook; - Understand and memorize the definitions of all key
terms; Write in your notebook (homework section) the key terms
and their definitions and some notes that you consider will help with the “do now” and they will meet the objectives
Solve for yourself all the questions and problems given by the textbook at the end of each section.
Assignments Watch the PPT at least 2 times or read the textbook; Understand and memorize the definitions of all key terms; Write in your notebook (homework section) the key terms
and their definitions and some notes that you consider will help with the “do now” and they will meet the objectives
Solve for yourself all the questions and problems given by the textbook at the end of each section.