Safety, Equipment, Measurement & Scientific Method

Safety, Equipment, Safety, Equipment, Measurement & Scientific Measurement & Scientific

MethodMethod

I. Science Standards for I. Science Standards for AHSGE (See Handout)AHSGE (See Handout)

1 Select appropriate laboratory glassware, balances, time 1 Select appropriate laboratory glassware, balances, time measuring equipment and optical instrument to conduct an measuring equipment and optical instrument to conduct an experiment.experiment.

1a Describing the steps of the scientific method.1a Describing the steps of the scientific method.

1b Comparing controls, dependent variables, and independent 1b Comparing controls, dependent variables, and independent variables.variables.

1c Identify safe laboratory procedures when handling chemicals 1c Identify safe laboratory procedures when handling chemicals and using Bunsen burners and laboratory glassware. and using Bunsen burners and laboratory glassware.

1d Using appropriate SI units for measuring length, volume, and 1d Using appropriate SI units for measuring length, volume, and mass.mass.

II. Safety Procedures in the II. Safety Procedures in the LabLab

A. Before working in the lab, fully read A. Before working in the lab, fully read all of the directions for the experiment.all of the directions for the experiment.

B. Be sure that you wear appropriate B. Be sure that you wear appropriate clothing for the lab and remove any clothing for the lab and remove any dangling jewelry.dangling jewelry.

C. Know where all safety equipment, C. Know where all safety equipment, including eyewash and fire including eyewash and fire extinguisher, are located.extinguisher, are located.

II. Safety Procedures in the II. Safety Procedures in the LabLab

D. Decide what personal D. Decide what personal protective equipment - like protective equipment - like aprons, goggles or gloves - are aprons, goggles or gloves - are necessary.necessary.

E. If there is an accident, spill or E. If there is an accident, spill or breakage in the lab, report it to breakage in the lab, report it to your instructor immediately.your instructor immediately.

III. See Lab Safety III. See Lab Safety HandoutHandout

A. Glassware SafetyA. Glassware Safety B. Sharp Instrument SafetyB. Sharp Instrument Safety C. Fire and Heat SafetyC. Fire and Heat Safety D. Animal SafetyD. Animal Safety E. Electrical SafetyE. Electrical Safety F. Chemical SafetyF. Chemical Safety G. Eye and Face SafetyG. Eye and Face Safety H. Proper DressH. Proper Dress

IV. OSHAIV. OSHA A. Through the A. Through the

Department of Department of Labor, the U.S. Labor, the U.S. Government runs Government runs the the Occupational Occupational Safety and Health Safety and Health AdministrationAdministration ((OSHA)OSHA)..

IV. OSHAIV. OSHA

B. The goal of OSHA is to B. The goal of OSHA is to protect the health and safety protect the health and safety of America’s workers.of America’s workers.

V. MSDS V. MSDS A. Manufacturers of chemicals A. Manufacturers of chemicals

are required to produce, update are required to produce, update and maintain a safety data sheet and maintain a safety data sheet for each chemical they produce. for each chemical they produce. This document is called a This document is called a material material safety data sheet (MSDS)safety data sheet (MSDS)..

V. MSDSV. MSDS B. MSDS lists info on chemical B. MSDS lists info on chemical

structure, chemical appearance, structure, chemical appearance, chemical properties, personal chemical properties, personal safety, safe storage and disposal safety, safe storage and disposal of chemicals.of chemicals.

C. See Figure 1.1 Example of an C. See Figure 1.1 Example of an MSDSMSDS

Complete Complete Section Section Review 1: Safety Review 1: Safety Procedures in the Procedures in the LabLab

VI. See Equipment and VI. See Equipment and Materials HandoutMaterials Handout

A. Mechanical pan balanceA. Mechanical pan balance K. Hot plateK. Hot plate B. Erlenmeyer flaskB. Erlenmeyer flask L. Triple-beam balanceL. Triple-beam balance C. Test tubesC. Test tubes M. Spring scaleM. Spring scale D. Graduated cylindersD. Graduated cylinders N. BeakersN. Beakers E. EyedropperE. Eyedropper O. TelescopeO. Telescope F. Bunsen burnerF. Bunsen burner P. Meter stickP. Meter stick G. Watch glassG. Watch glass Q. Fume hoodQ. Fume hood H. ThermometersH. Thermometers R. MicroscopeR. Microscope I. Petri dishI. Petri dish S. Wire gauzeS. Wire gauze J. TongsJ. Tongs T. TripodT. Tripod

Discuss the Discuss the ActivityActivity

Complete Complete Section Review 2: Section Review 2: Equipment Equipment

VII. Scientific MeasurementVII. Scientific Measurement A. Introduction to SI A. Introduction to SI

UnitsUnits 1. The 1. The SI unitsSI units of of

measurement are measurement are used throughout used throughout the world when the world when performing performing calculations related calculations related to scientific to scientific investigations.investigations.

VII. Scientific VII. Scientific MeasurementMeasurement

2. It stands for 2. It stands for Le Systeme Le Systeme International d’ UnitesInternational d’ Unites and and was established in France was established in France about 200 years ago.about 200 years ago.

VII. Scientific MeasurementVII. Scientific Measurement B. SI units were adapted from B. SI units were adapted from

the metric system, and the base the metric system, and the base units are:units are:1. 1. MeterMeter – to measure length – to measure length2. 2. GramGram – to measure mass – to measure mass3. 3. SecondSecond – to measure time – to measure time

VII. Scientific MeasurementVII. Scientific Measurement C. The C. The English systemEnglish system, , U.S. U.S.

Customary SystemCustomary System, of , of measurement is used in the U.S.measurement is used in the U.S.1. 1. FootFoot – the standard length – the standard length2. 2. PoundPound – the standard weight – the standard weight3. 3. SecondSecond – the standard for – the standard for

timetime

VII. Scientific VII. Scientific MeasurementMeasurement

D.**The SI units are used in the D.**The SI units are used in the scientific community and scientific community and throughout the world.**throughout the world.**

E. See Table 1.1 Unit E. See Table 1.1 Unit ConversionsConversions

VIII. Unit ConversionsVIII. Unit Conversions A. The units in the metric system A. The units in the metric system

are defined in multiples of 10 from are defined in multiples of 10 from the standard unit.the standard unit.

B. The metric prefixes indicate B. The metric prefixes indicate which multiple of 10 ~ 10, 100, or which multiple of 10 ~ 10, 100, or 1,000 ~ the standard unit should 1,000 ~ the standard unit should be multiplied or divided by.be multiplied or divided by.

VIII. Unit ConversionsVIII. Unit Conversions1. 1. MultiplyMultiply when changing from when changing from

a greater unit to a smaller one.a greater unit to a smaller one.2. 2. DivideDivide when changing from when changing from

a smaller unit to a larger one. a smaller unit to a larger one. C. See Unit Conversions C. See Unit Conversions

ExamplesExamples

Discuss the Discuss the ActivityActivity

Complete Complete Practice Practice Exercise 1: Unit Exercise 1: Unit ConversionsConversions

IX. Standard SI MeasurementsIX. Standard SI Measurements A. LengthA. Length

1. The standard SI unit of 1. The standard SI unit of measurement to determine measurement to determine lengthlength is is meter (m)meter (m)..

2. A 2. A rulerruler (used to measure feet) or (used to measure feet) or meter stickmeter stick (used to measure meters) (used to measure meters) is commonly used to measure is commonly used to measure lengthlength. .

3. See Figure 1.2 Metric Ruler3. See Figure 1.2 Metric Ruler

IX. Standard SI MeasurementsIX. Standard SI Measurements

B. MassB. Mass 1. 1. MassMass is the measure of the amount of matter is the measure of the amount of matter

in an object.in an object. 2. The standard SI measurement unit is the 2. The standard SI measurement unit is the

kilogram (kg)kilogram (kg) and the tool is the and the tool is the balancebalance..

IX. Standard SI IX. Standard SI MeasurementsMeasurements

C. Mass vs WeightC. Mass vs Weight1. The terms 1. The terms massmass and and weightweight

are sometimes used are sometimes used interchangeably, but they are not interchangeably, but they are not the same.the same.

2. 2. MassMass is a property of the is a property of the object itself.object itself.


3. 3. WeightWeight is the measurement of is the measurement of the gravitational force that the gravitational force that attracts an object to the earth.attracts an object to the earth.

4. The SI unit for 4. The SI unit for weightweight is the is the newton (N)newton (N), and in the English , and in the English system of measurement, system of measurement, weightweight is given in is given in pounds (lbs.)pounds (lbs.) or or ounces (oz.)ounces (oz.)..


D. Volume D. Volume 1. 1. VolumeVolume is the amount of space is the amount of space

occupied by an object.occupied by an object.2. 2. VolumeVolume is determined in different is determined in different

ways depending on the ways depending on the shapeshape (cube, sphere, irregular) and (cube, sphere, irregular) and state of state of mattermatter (solid, liquid, gas) of the (solid, liquid, gas) of the object.object.


3. For a 3. For a regularly shaped objectregularly shaped object, , like a cube, volume is like a cube, volume is determined by determined by multiplyingmultiplying the the lengthlength times the times the heightheight times the times the widthwidth of the object of the object

(V = l x h x w).(V = l x h x w).


4. The units used for 4. The units used for volumevolume are are cubic centimeterscubic centimeters (cm (cm33 or cc) or or cc) or millilitersmilliliters (mL). (mL).

5. See Figure 1.3 Volume of a Cube5. See Figure 1.3 Volume of a Cube 6. A 6. A graduated cylindergraduated cylinder is used to is used to

measure the volume of measure the volume of liquidsliquids.. 7. See Figure 1.4 Graduated 7. See Figure 1.4 Graduated

Cylinder Cylinder


8. To determine 8. To determine volumevolume of of irregularly shaped objectsirregularly shaped objects, the , the water displacement methodwater displacement method is is used. used.

9. See Figure 1.5 Water 9. See Figure 1.5 Water Displacement MethodDisplacement Method


E. DensityE. Density 1. Density (D) is the mass (m) of an 1. Density (D) is the mass (m) of an

object divided by its volume (V), object divided by its volume (V), (D = m / V). (D = m / V). 2. The standard SI unit for density is 2. The standard SI unit for density is kg / mkg / m33, but it is also commonly , but it is also commonly

expressed in units of grams per cubic expressed in units of grams per cubic centimeter (g / cmcentimeter (g / cm33).).

3. See Figure 1.6 Mass - Density 3. See Figure 1.6 Mass - Density RelationshipRelationship

IX. Standard SI MeasurementsIX. Standard SI Measurements

F. TemperatureF. Temperature1. 1. TemperatureTemperature measures measures

how hot or cold something is. how hot or cold something is. 2. All measurements for 2. All measurements for

temperature are taken in temperature are taken in degreesdegrees..

IX. Standard SI MeasurementsIX. Standard SI Measurements3. In the metric system, 3. In the metric system, CelsiusCelsius

(C) is used.(C) is used.4. The SI unit for temperature is 4. The SI unit for temperature is

KelvinKelvin (K), and the English unit is (K), and the English unit is FahrenheitFahrenheit (F). (F).

5. See Figure 1.7 Temperature 5. See Figure 1.7 Temperature Conversion FormulasConversion Formulas

X. Designing & Conducting X. Designing & Conducting an Experimentan Experiment

A. ScienceA. Science1. 1. ScienceScience is the observation, is the observation,

identification, description & identification, description & explanation of phenomena.explanation of phenomena.

2. The Latin root for the word 2. The Latin root for the word “science” is “science” is scientia, scientia, meaning meaning knowledge.knowledge.

X. Designing & Conducting X. Designing & Conducting an Experimentan Experiment

B. Scientific MethodB. Scientific Method1. The 1. The scientific methodscientific method is a is a

procedure for studying nature.procedure for studying nature.2. See Table 1.2 & Figure 1.8 2. See Table 1.2 & Figure 1.8

Steps in the Scientific MethodSteps in the Scientific Method

XI. Making Observations & XI. Making Observations & Defining the Problem (Step 1)Defining the Problem (Step 1)

A. A A. A natural phenomenonnatural phenomenon is is something occurring in nature that something occurring in nature that we experience through our we experience through our senses.senses.

B. The B. The scientific processscientific process is used is used to research & explain natural to research & explain natural phenomena.phenomena.

XI. Making Observations & XI. Making Observations & Defining the Problem (Step 1)Defining the Problem (Step 1) C. Observations are made by C. Observations are made by

using the using the 5 senses5 senses (sight, touch, (sight, touch, smell, sound & taste) to obtain smell, sound & taste) to obtain info.info.1. Ex. - Observe birds in flight. 1. Ex. - Observe birds in flight. 2. See Figure 1.9 Different Bird 2. See Figure 1.9 Different Bird

Behaviors for ObservationBehaviors for Observation

XI. Making Observations & XI. Making Observations & Defining the Problem (Step 1)Defining the Problem (Step 1)

D. Making D. Making observations observations may lead to may lead to identifying identifying problems as problems as well.well.

XI. Making Observations & XI. Making Observations & Defining the Problem (Step 1)Defining the Problem (Step 1)1. 1. ObservationObservation - pigeons are - pigeons are

making nests on the tops of city making nests on the tops of city buildings.buildings.

2. 2. ProblemProblem – pigeon droppings are – pigeon droppings are damaging shingles & defacing city damaging shingles & defacing city property, as well as possibly property, as well as possibly spreading disease.spreading disease.

XII.XII. Asking Questions Asking Questions (Step 2)(Step 2)

A. By asking A. By asking questions, we can questions, we can search for logical search for logical explanations for explanations for what we observe what we observe & find ways to & find ways to solve problems.solve problems. 1. Ex. – How 1. Ex. – How

do birds fly?do birds fly?

XIII. Forming a Hypothesis XIII. Forming a Hypothesis (Step 3)(Step 3)

A. A A. A hypothesishypothesis is a statement is a statement that gives the best possible that gives the best possible response to the question & should response to the question & should be based on already known facts.be based on already known facts.

B. It is an educated guess.B. It is an educated guess.1. Ex. – The wing designs of 1. Ex. – The wing designs of

birds catch air differently.birds catch air differently.

XIII. Forming a Hypothesis XIII. Forming a Hypothesis (Step 3)(Step 3)

C. The hypothesis can be C. The hypothesis can be developed by using inductive developed by using inductive reasoning. reasoning. 1. 1. Inductive reasoningInductive reasoning is the is the

ability of a scientist to draw from ability of a scientist to draw from knowledge & experience to knowledge & experience to make a general explanation.make a general explanation.

XIV. Setting Up the XIV. Setting Up the Experiment (Step 4)Experiment (Step 4)

A. A A. A scientific experimentscientific experiment should should give accurate & measurable results.give accurate & measurable results.

B. An experiment should be B. An experiment should be designed to collect info to either designed to collect info to either prove or disprove the hypothesis.prove or disprove the hypothesis.

C. To gather meaningful data, the C. To gather meaningful data, the experiment must be set up to experiment must be set up to examine only 1 condition (or examine only 1 condition (or variablevariable) at a time.) at a time.


C. To test the hypothesis, the C. To test the hypothesis, the experiment should have 2 experiment should have 2 components: a control group components: a control group & 1 or more experimental & 1 or more experimental groups.groups.


1. The 1. The control groupcontrol group is the part is the part of the experiment that is of the experiment that is designed without changing any designed without changing any of the variables. This helps to of the variables. This helps to support the hypothesis.support the hypothesis.


2. The 2. The experimental groupsexperimental groups are are designed to test components of the designed to test components of the hypothesis & to indicate changes hypothesis & to indicate changes which might invalidate the which might invalidate the hypothesis.hypothesis.

3. See Table 1.3 Conditions (& 3. See Table 1.3 Conditions (& Variables) for Radish Seed Variables) for Radish Seed Experiment Experiment


D. There are 3 types of variables seen D. There are 3 types of variables seen in an experiment:in an experiment: 1. 1. independent variableindependent variable – the – the

factors that are changed or factors that are changed or manipulated during the experiment. manipulated during the experiment. They are the ones that the experiment They are the ones that the experiment is trying to test.is trying to test.a. Ex. – presence or absence of a. Ex. – presence or absence of lightlight


2. 2. dependent variabledependent variable – it is – it is usually the factor that the usually the factor that the experimenter is measuring or experimenter is measuring or counting. It is the 1 that changes in counting. It is the 1 that changes in response to the independent response to the independent variable.variable.a. Ex. – the # of radish seeds that a. Ex. – the # of radish seeds that germinatedgerminated


3. 3. control variablecontrol variable – all the other – all the other factors in the experiment. These are factors in the experiment. These are things that you attempt to control. things that you attempt to control. The following are all considered The following are all considered control variables & are kept constant.control variables & are kept constant.a. Ex. – temperature, amount of a. Ex. – temperature, amount of moisture present, type of light bulb moisture present, type of light bulb or length of time the experiment ranor length of time the experiment ran

XV. Collecting DataXV. Collecting Data A. Data could include time intervals, A. Data could include time intervals,

temperatures & metric units of mass, temperatures & metric units of mass, length & volume.length & volume.

B. B. Qualitative dataQualitative data is info that is info that cannot be assigned a numerical cannot be assigned a numerical value. It is often collected using the 5 value. It is often collected using the 5 senses.senses.1. Ex. – shades of color, texture, 1. Ex. – shades of color, texture,

taste or smelltaste or smell

XV. Collecting DataXV. Collecting Data C. C. Quantitative dataQuantitative data is anything that is anything that

can be expressed as a #, that is, it can can be expressed as a #, that is, it can be quantified.be quantified. 1. Ex. – lengths, weights, masses, 1. Ex. – lengths, weights, masses,

volumes, time or anything else volumes, time or anything else expressed as a #expressed as a #

2. Both qualitative & quantitative data 2. Both qualitative & quantitative data can be organized in a data table.can be organized in a data table.

3. See Table 1.4 # of Radish Seeds 3. See Table 1.4 # of Radish Seeds Sprouted over 7 DaysSprouted over 7 Days

XVI. Drawing ConclusionsXVI. Drawing Conclusions A. A A. A conclusionconclusion is a judgment or is a judgment or

inference based on observation & inference based on observation & experimentation.experimentation.1. It is drawn from the results of the 1. It is drawn from the results of the

experiment.experiment.2. The 2. The resultsresults are the end product are the end product

of an experiment.of an experiment.

XVI. Drawing ConclusionsXVI. Drawing Conclusions B. The analytical method of B. The analytical method of

investigation is an examination of investigation is an examination of parts of an experiment to seek parts of an experiment to seek reliable info that will support or reliable info that will support or reject the hypothesis.reject the hypothesis.

XVI. Drawing XVI. Drawing ConclusionsConclusions

C. To really know the true C. To really know the true outcome of an experiment, it outcome of an experiment, it must be performed many times.must be performed many times.1. Through the analysis of 1. Through the analysis of

results obtained from all results obtained from all experiments, a summary or experiments, a summary or conclusion can be determined.conclusion can be determined.

Complete Complete Practice Practice Exercise 2: Drawing Exercise 2: Drawing ConclusionsConclusions

Section 3: Designing Section 3: Designing & Conducting an & Conducting an ExperimentExperiment

ReviewReview

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Safety, Equipment, Measurement & Scientific Method