Objective 1 Review

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Objective 1 Review

• This objective tests historical scientific
  development, method, safety and equipment.
• Answer the questions, and check your answers, for
  each question you miss, review the material by
  slide numbers on the Table of Contents

2
Sample question 1

• The ingredients described above are used to make
  a bonding agent. The most important safety
  precaution to take when applying this bonding
  agent is to
• A dry it with a small flame
• B work in a well-ventilated area
• C cover the work area with newspaper
• D wear a lab coat

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Sample question 2
4
Sample 3 Four lab groups measured the volume of
acid required to neutralize a standard solution
of sodium hydroxide base. Which of the groups
measured the volume with the highest precision?
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Sample Question 4
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Check your answers

• B Safety
• F Inference
• D Precision
• B Equipment
• If you missed a question, refer to the section
  for review, and take the practice quiz at the end
  of this presentation.

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Sample Question 2 What conditions determine the
answer?

• Pressurized cabin, so there is more air inside
  than outside. Air will not come in, so . . . Not
  H
• Weightless, so there is near zero gravity. If
  there is not any gravity does anything fall down?
  Not G
• Pumping a sprayer does not put more pressure in
  the cabin since it releases water droplets. Not J
  
• Correct answer F

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Sample 3 What equipment is used to measure
volume?

• In A, they are using two flasks. Not very
  precise markings!
• B is better, at least they are using a graduated
  cylinder.
• C is a bad choice, since most test tubes have no
  markings for volume.
• D is the best choice as the small volume markings
  on the burette gives the most precise
  measurement.

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Sample 4 What can be eliminated?

• 10 mL test tube too small . . . Not A
• 100 mL graduated cylinder. When heated water
  expands so it will be greater than 100 mL and
  spill. . . . Not C
• 300 mL SEALED flask never heat in a sealed
  container, so not D. . .
• Therefore it is B

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Table of Contents
Section to Review Slide

• Science vs. Technology
• History of Science and Contributors
• Safety Rules and Equipment Use
• Safety
• Accuracy and Precision

• 11
• 12 19
• 20-22
• 23-26
• 27-30

11
Science vs. Technology

• Science is the knowledge gained from
  experimentation.
• Newtons Laws
• Theory of Relativity
• Ohms Law
• Human Genome Project

• Technology is the use of science knowledge to
  make things.
• Calculators computers
• Atomic Energy
• Electric motors
• Gene therapy
• Antibiotics

12
A Brief History of Science

• Ancient Greek and Roman philosophers began
  observing and recording their observations of the
  world around them.
• They tried to propose how and why these things
  occurred.

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These observations led to more questions . . .

• which led to proposed answers, now called
  hypotheses

14
Names and Contributions

• Aristotle Greek philosopher and naturalist
  provided philosophical basis of science which
  proved dominant for 18 centuries.
• Neils Bohr - The Bohr model of the atom gave a
  good 'fit' with the observed spectra for the
  simplest atoms (hydrogen and helium) and it was
  much modified later, but the concept was a
  milestone for physics and for chemistry.
• Marie Curie Credited as the first to discover
  radioactive properties.

15

• Charles Darwin - British naturalist developed a
  general theory of evolution and natural selection
  of species.
• John Dalton - First real model of the atomic
  concept, explained that atoms of one element are
  all alike
• Democritus - First to use a word atom to
  describe what all things are made of
• Albert Einstein - German-Swiss-US theoretical
  physicist conceived the theory of relativity.

16

• Enrico Fermi - Italian-US nuclear physicist
  built first atomic reactor.
• Galileo Inventor of the telescope and first to
  describe the solar-central solar system.
• Robert Hooke inventor of the compound
  microscope. He used the word 'cell' to describe a
  thin section of cork, and the word has come to be
  used for the membrane-bound units of plant and
  animal life.

17

• Carolus Linnaeus - Swedish botanist the great
  classifier of plants popularized binomial
  nomenclature for classification of living things.
• Dimitri Mendeleve Credited as the first to
  organize the periodic table of the elements.
• Issac Newton - Laid the foundation for future
  achievements in optics, mathematics, and
  dynamics. He published his Principia in 1687

18

• George Ohm - German physicist discovered
  relationship between current and voltage in a
  conductor.
• Ernest Rutherford - Gold Foil Experiment, showed
  that atoms are mostly empty space, that a nucleus
  is very dense and positively charged.
• Robert Seaborg Corrected the periodic table to
  the modern version we use today, with inner
  transition metals.

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And by no means last . . .

• J.J. Thompson - Plum Pudding Model which showed
  a negative charge flowing over the outside
  surface of an atom.
• Watson Crick - The structure of DNA was
  discovered by geneticists James Watson and
  Francis Crick in 1953.

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Three levels of science knowledge

• Hypothesis a possible explanation of observed
  information
• Theory an explanation that has been repeatedly
  tested by experimentation
• Law After a theory has been the same for a few
  hundred years it becomes a law

21
Scientific Theory

• Theories are based upon experimental data.
• Confirmed by repeated experiments.
• Modified as new information is gathered.
• Must have repeated data confirmations not just
  an idea.

22
Scientific Law

• Theories become Laws when all available data
  support the theories for long periods of time
  (hundreds of years).
• Laws become theories again when new information
  changes them.

23
Experimentation and Safety

• Use only labeled materials.
• Read labels twice to make sure.
• Know the procedure.
• Ask about the MSDS if you are not familiar with
  the substance.

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Safety with Temperature Changes

• Do not handle hot or cold containers without
  proper protection.
• Use the proper holder for the container.
• When heating a substance, aim it away from
  everyone, including yourself.

25
Safety with Gases

• Odors are tested by wafting.
• Reactions which produce volatile, flammable, or
  toxic gases should be done in a fume hood.
• Gases should be trapped only in a large volume
  container to provide for rapid expansion.

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Safety Equipment

• Protective goggles are worn in lab at all times.
• Non-ventilated goggles are worn if contact lenses
  are worn.
• Aprons should be worn when handling chemicals.
• Follow MSDS guidelines for safe handling of all
  chemicals.

27
Accuracy

• This is when a measurement is closest to its true
  value.
• Several thermometers reading exactly the same
  temperature would indicate that the readings are
  more likely to be accurate.

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Precision

• This is the repeatability of a measurement.
• It may or may not be accurate
• But everyone who does it gets the same or nearly
  the same measurement or reading

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Is it accurate? Is it precise?

• Accuracy depends on how close the measurement
  tool is to the actual.
• If the equipment has been properly calibrated and
  cared for it is usually accurate.

• Precision is repeatability and usually depends on
  the amount of estimating that has to be done.
• The smaller the measurement markings on the tool,
  the more precise it is.

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Accuracy vs. Precision

• Which of the following will allow measurement of
  a liquids volume with the greatest precision?
• A 50 mL cylinder graduated in 1 mL increments
• B 50 mL cylinder graduated in 0.5 mL increments
• C 100 mL cylinder graduated in 1 mL increments
• D 200 mL cylinder graduated in 5 mL increments

Answer B
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Lets try a few more. . .

• The next 7 slides check to see if you have
  mastered the ideas presented.
• If you do not understand the answer after it has
  been explained, please ask one of the teachers
  present for help.

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• What are the warnings?
• Repeatedly the word vapors appears, so that is
  what is most important to guard against.
• Which answer reduces the risk most?

• The ingredients described above are used to make
  a bonding agent. The most important safety
  precaution to take when applying this bonding
  agent is to
• A dry it with a small flame
• B work in a well-ventilated area
• C cover the work area with newspaper
• D wear a lab coat

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(No Transcript)
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When sampling an area, do you want a pattern, or
no pattern?

• Plants drop seeds, or send out runners, so
  sampling near a plant would probably give you the
  same plant again.
• Random would be best, and most reliable so . . .
  B

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• An engineer has created a new engine for race
  cars. It is necessary to know which fuel mixture
  will allow the engine to run at its peak
  performance. Which experimental design is best
  for this investigation?
• F Use one fuel mixture on the engine and measure
  its performance
• G Use one fuel mixture on many type of engines
  and measure their performance
• H Use various fuel mixtures on the engine and
  measure its performance
• J Use various fuel mixtures on many types of
  engines and measure their performance

Analyze the question. . . which fuel mixture
that means test several various fuels. We know
which engine so it must be H.
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• 55 A science class is conducting an experiment
  that produces noxious fumes. Because of
  inadequate ventilation, some students begin to
  feel nauseated and dizzy. The first response
  should be to
• A neutralize the acid that is reacting to produce
  the noxious fumes
• B carry the reactants outside, away from other
  students
• C leave the room and go to an area with fresh air
• D spray the reaction with a fire extinguisher

Not A Acids are not the only producers of
fumes, and adding something else could make it
worse!
Dont move it anywhere except under a fume hood,
Too dangerous! Not B
Not D --Extinguishers should only be used on
fires.
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The reason for wafting or fanning a small amount
of chemical vapors toward the nose as a means to
detect odors in a test tube is to

• (A) avoid experimental error from excessive
• loss of mass of reactants or products
• (B) avoid splashing chemicals into the face of
• any person
• (C) protect the respiratory tract against
  potentially harmful vapors
• (D) determine the relative strength of the
• odor before smelling directly

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Laboratory equipment is cleaned and properly
stored after use primarily so that

• (A) chemical products can be measured and
• recorded as data
• (B) time is saved in setting up the next
• experiment
• (C) toxic materials can be kept in the
• laboratory
• (D) the possibility of contamination in the
• laboratory is minimized

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Which of the following pieces of equipment would
be most appropriate for measuring the volume of a
marble?
Answer B
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For the next questions write your answers on a
sheet of paper under the heading Obj. 1.1 with
your name and Science Teacher. Turn it in to
receive your Bonus Bucks. . .
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1.
TAK Obj. 01 TEKS B.1A
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• 2. Which question could be formed based on these
  data
• A. What types of plants have increased
  productivity in difficult habitats.
• Is there a relationship between productivity and
  bird diversity in a habitat?
• How does the number of birds in a population
  affect habitats?
• Do habitats display changes in productivity and
  bird diversity during different seasons?

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• 3. Which of the following was probably the
  hypothesis for this experiment?
• The growth of bread mold increases as the
  temperature increases.
• The type of nutrient causes bread mold to grow
  faster at higher temperatures.
• The size of the plates determines the temperature
  of bread mold.
• The temperature of bread mold is determined by
  the molds growth.

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4.
TAK Obj. 01 TEKS B.2A
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TAK Obj. 01 TEKS B.1A
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6.
TAK Obj. 01 TEKS B.1A
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7.
TAK Obj. 01 TEKS I.3A
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Now, check your answers. If you missed a
question, attend an Objective 1 tutorial session.

• D
• B
• A
• B
• A
• D
• B