What is “Science?”
Why do we really need to study it?
Field and lab investigations
• Science is a process
• We begin with a question, and seek an answer
by investigating the natural world
• We use a variety of methods to investigate
– Conduct experiments
– Work of other scientists
• We use tools (lab equipment) to help us find
the answers we seek
What correlation do the following
have with concerning ourselves with
“lab safety?”
• Falling down the stairs
• Slipping on water
• Getting robbed
THAT BAD THINGS CAN
HAPPEN AT ANY TIME AND
WE WANT TO PREVENT
THOSE THINGS FROM
HAPPENING IN LAB.
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Never eat or drink in the lab.
Remain alert at all times.
Keep your area free of clutter.
Follow both written and verbal directions.
Unauthorized experiments can be
dangerous.
• Report any accident, incident, or hazard to
me immediately, even if you think it’s “no
big deal.”
• Students may not work alone.
• Remain at your workstation.
The world
needs more
Lerts!
• Always wear goggles and other safety items.
• If you get any chemical in your eyes,
immediately flush your eyes (including under
your eyelids) with water at the eyewash
station for at least 15 minutes. Notify your
teacher.
• Secure all loose items.
• Hair should be pulled back.
• Contacts are now allowed.
• Know where to find the safety equipment.
Where are the following pieces of
safety equipment found in our room?
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Fire extinguisher
Safety shower
Eye wash
Fire blanket
What are each of them used for?
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Fire extinguisher
Safety shower
Eye wash
Fire blanket
• To put out a fire if your
clothes are on fire
• To put out a fire in the
room (i.e. paper)
• To use if you get
something hazardous on
your body
• To use if you get
something harmful in your
eye(s)
Blood and Body
Fluids Safety
• Wear gloves when someone is bleeding or
vomiting
• Clean everything touched by blood or vomit with a
disinfectant
• Remove your latex gloves by pulling them off inside out
• All materials used to clean up blood or other possible
infectious materials should be disposed of in the proper
biohazardous waste bag
• Standard Biohazardous waste bags are red with the
biohazardous waste symbol on them. If one is not
available, use a regular plastic garbage bag and attach
biohazardous waste sticker to the bag
• Wash your hands thoroughly with a disinfectant when you
are finished
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Never pipette by mouth.
Throw away broken or chipped glassware
Hot glass looks like cool glass.
Hot glass does not go in water.
Point test tubes away from people when heating them.
Always pour acid into water.
Touch electrical devices only with dry hands.
Smell a chemical by waving your hand over it and
letting the smell drift to your nose.
Don’t pour chemicals down the sink.
Never return unused chemicals to the original container.
What do the following symbols
represent?
Safety Warning Symbols
Safety Warning Symbols
Cool!
Oops, I was supposed to
read the lab directions
first!!!!
What does M.S.D.S. stand for?
Why do we use them during lab?
• Material Safety Data Sheets
• It provides information on the safe use,
handling, storing, and potential hazards of a
chemical.
Examples of why it’s important to
know what types of chemicals
you’re dealing with and how to store
them:
• Generation of heat (acids & bases)
• Violent reaction (acrolein & acids or other
catalyst)
• Formation of toxic vapors or gases (cyanide salt &
acid)
• Formation of a flammable gas (alkali metal &
water)
• Fire or Explosion (perchloric acid & acetic
anhydride)
Safety Terms:
Caustic or corrosive- Will
corrode or eat away metal,
skin, or other substances.
Volatile- Evaporates quickly,
may form dangerous vapors.
Flammable (may ignite)will catch on fire or explode
easily.
Ventilation- removing
contaminated air and brining
in fresh air.
Where have you seen the
following sign before?
NFPA Hazard Diamond
• Inside/outside of labs
• On chemical bottles
• On trucks (gases,
different chemicals)
• Hair salons
Flammability
Hazard
Health
Hazard
All chemicals must
be labeled, and the
label must include
the NFPA hazard
diamond
Stability
Hazard
Special
Information
Risk Level
0 Minimal
1 Slight
2 Moderate
3 Severe
4 Extreme
How dangerous is this one?
Extremely flammable
Moderately unstable
Not a health risk
Keep away from water
4
0
2
W
•Extinguishers must be located and marked so
they are easily seen in a laboratory
•The extinguisher must be inspected annually
and be tagged with the inspection history
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Triple Beam Balance
• To measure the mass of substances or
objects accurately
• Mass is the amount of matter in an object.
Graduated cylinder
• To measure volume of liquids
accurately to within about
1%.
• They are for general purpose
use, but not for quantitative
analysis. If greater accuracy is
needed, use a pipette or
volumetric flask.
• The guard is to protect it from
breaking if it tips over
The Meniscus—reading volume correctly
• When water is placed in a
glass or plastic container the
surface takes on a curved
shape.
• This curve is known as a
meniscus. Volumetric
glassware is calibrated so
that reading the bottom of
the meniscus viewed at eye
level gives accurate results.
• Viewing the meniscus at any
other angle will give
inaccurate results.
SI Ruler
(“Metric” is slang.)
• To measure the lengths of
solid objects accurately
SI thermometer
• To measure temperature accurately
• Metric units are degrees Celsius, oC
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Magnifying glass
(hand lens)
• To make objects appear
larger than they are
Bunsen burner
• To heat substances (with a flame)
Hot plate
• To heat substances using electricity, not a flame
• This is usually safer when heating chemicals
Ring stand
with clamp and ring
• To hold containers away
from a heat source during an
experiment
Safety goggles
• To protect eyes against
burns, cuts, or flying objects
Microscope
• To view specimens that
are too small to see with
the naked eye
Compound microscope
Eyepiece
Body tube
Revolving nosepiece
Low power objective
Coarse adjustment
(focus)
Fine adjustment
(focus)
Arm
Stage Clip
High power objective
Stage
Mirror (or light source)
Diaphragm (controls
amount of light)
Base
http://www.cat.cc.md.us/courses/bio141/labmanua/intro/stageslide.html
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Microscope Slide
• To hold a specimen (sample) for viewing
through a microscope
http://www.scitoys.com/scitoys/scitoys/thermo/liquid_metal/liquid_metal.html
Cover slip
• To cover a specimen (or sample) on a slide
Medicine dropper
(Eyedropper)
• To drop small amount of liquids
http://www.dryeye.org/products.htm
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Forceps
• To pick up small items that you should not
touch
Petri dish
• To grow bacteria
and other tiny living
things
Test tube
• To hold liquids and chemicals
during experiments
(investigations)
Test tube rack
• To hold test tubes during
an investigation. (After
cleaning, test tubes can be
placed upside down to
dry.)
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Test tube clamp
• To hold test tubes over heat
or away from your body
Erlenmeyer flask
• Used for mixing,
transporting, and reacting,
but not for accurate
measurements.
• The volumes stamped on
the sides are approximate.
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Florence flask
• Used for mixing, transporting, and
reacting, but not for accurate
measurements.
• The volumes stamped on the sides
are approximate.
Beaker
• Used for mixing, transporting, and reacting,
but not for accurate measurements.
• The volumes stamped on the sides are
approximate
Tongs
• To pick up large objects that you should not
touch (e.g., hot containers, flasks of acids,
etc.)
Funnel
To pour liquids or powders
from one container to
another without spilling
anything
Stirring rod
To mix chemicals and hot
liquids together by stirring
Accurate measurement
When measuring distance on the TAKS
•You will have a ruler on the side of
your formula sheet.
•USE IT if you are asked to measure
distance on a map or a length.
Measure the length of a
tile.
Measure the width of your
folder.
What is the volume of liquid in this graduated cylinder?
29 mL
When taking the
mass of solids
•Use a mass boat or
paper.
•Subtract out the mass
of the container or paper
to zero the balance.
•Clean up spills so they
don’t corrode the
balance.
Reading Graphs and Making Calculations
•Scientists must
analyze graphs to
understand an
experiment’s result.
• The Dependent
variable is on the Yaxis.
•The Independent
Variable on a graph is
on the X-axis.
Pie Graphs
• Pie graphs are used
to show how a
whole is broken up
into its parts.
• Note that parts
should add up to
100% when values
are given
Bar Graphs
• Bar graphs are used to compare
measurements taken from a number of
objects or categories.
• They demonstrate trends in data
Line Graphs
• Most graphs show the
relationship between two
variables.
• The lines are usually drawn
either straight or curved.
• These "smoothed" lines do
not have to touch all the data
points, but they should at
least get close to most of
them. They are called bestfit lines
Pictographs
Pictographs use symbols
to represent numbers.
Always check keys and
legends to accurately read
units and labels on graphs.
Nutrition Labels
• A U.S. government agency defines what
information must appear on a food label.
• The meaning of terms such as “low fat” are
strictly defined for use on labels
– If a label claims that the product is
unsweetened or that there is no sugar added, it
means no common table sugar (sucrose) has
been added.
– It does NOT mean there are no other sugars
present
• Info is based on a single serving
– Careful, single servings are sometimes chosen
so that the numbers “look good” at a glance
check this when comparing two labels
– For example, an individual bag of chips may
have three servings, rather than one
•You may be asked to
calculate a % from a label.
•To find a %, divide the #
of items you have by the
total #, then multiply by
100.
Analyzing Product Ads (consumer info)
• Every day, companies try to sell you their products.
• Television commercials and newspaper and magazine
ads tell you why certain products are best.
• You must use your critical-thinking and problemsolving skills to decide for yourself if the ads are
correct.
– Remember—their motive is $$$ so they may
“shade” the truth to convince you; you have to
outsmart them!
Feel Better Fast with Vitaplex!--Really?
• The word “scientific” is to make you believe this is factual
• It’s true that your body needs protein to survive and that your
body converts protein into amino acids
• It is NOT true that excess protein will not be converted into fat
• Vitamins are essential to good health, but they do not provide
energy
• Excess vitamins are excreted or stored in the fat (too much
stored in fat can make you ill)
• So, will Vitaplex give you energy and make you feel better?
Scientific Process
• Prentice Hall – Chapter 1: Section 2
– Pages 8-15
Scientific Process
• Why does it rain? Give an answer without
using a scientific explanation.
• Suppose someone does not believe your
explanation. Could you supply evidence to
support your explanation?
Steps of the Scientific Method
• Purpose – Ask a question
• Form a Hypothesis
• Experimentation – Set up a controlled
experiment
• Record and Analyze data
• Draw a Conclusion
Scientific Method
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What is it?
A method of investigating questions
Why do we need it?
We must make decisions based on what we know
and observe NOT what we want it to be!
• Does it apply to us outside of the lab/classroom?
• Yes, of course! You use it all the time and
probably do not even realize it.
Scientific Method
Results may require
adjusting hypothesis
Observations
Hypothesis
Experiments
Theory
Cycle repeated until the hypothesis
fits all observed experimental facts
Observations
Explains results
Repeated successful
experiments
Law
Describes natural phenomena
Theory vs. Law
• What is the difference between a theory and
a law?
• Theory – well tested hypotheses proven
beyond reasonable doubt (however, they
can be disproven)
• Law – is a statement of fact meant to
explain a set of actions
Theory vs. Law
• Theory – explains nature.
• They answer the question: WHY does that happen?
• Law – describes nature.
• They answer the question: WHAT will happen?
• Laws and theories are different kinds of things.
Theories do not become laws. Laws do not
become theories. Ex: Lions do not become tigers.
Experimentation
• Experimental group
• Receives some kind of treatment or
condition (plant given miracle grow)
• Control group
• Receives no treatment, used to compare
results (plant not given miracle grow)
Why do we need a control group?
• To determine the actual affects that the
factors you are testing have on that group
Types of Variables
• Independent Variable (Manipulated
variable)
• The factor you change, what you do to your
group (Miracle Grow)
• Dependent Variable (Responding
variable)
• What happens as a result of that treatment,
what you are measuring (Growth of plant)