Transcript 1.3 (Lab Safety, Procedures). - stroh

Catalyst – January 27-8, 2012
1.
2.
Write a hypothesis to answer the following question:
How does the amount of sunlight affect the number of
oranges grown in the orchard?
Identify the independent and dependent variables in the
following scenario: Johnny thinks that he is a great poet,
but he gets nervous when he shares his work with others.
He believes that performing in a slam poetry event with the
Spoken Word Club at Higgins will help him overcome his
nerves.
Today’s Agenda
Catalyst
 Quick Variables Review
 Lab Safety and Cartoon
 Notes: Writing Quality Procedures/Methods
 Exit Question
HW: Write a procedure for something you
like to do or cook OR something you would
like to learn how to do

Today’s Objectives
SWBAT dominate variables and
experimental design.
 SWBAT describe basic lab safety
procedures.
 SWBAT plan a QUALITY step-by-step
method for making Mystery Goo.

REVIEW OF
VARIABLES!
Experimentation

Review: A proper experiment
always has an independent
variable and dependent variable.
 Variable:
a quantity or condition that can
have more than one value; variable means
change!
 Variables are CATEGORIES!
Variables
Independent Variable: variable that you
change during an experiment; causes the
change you are measuring; aka
manipulated variable (acts independently)
 Dependent Variable: variable that is
observed; changes in response to change in
IV; aka responding variable (depends on
other things)

Constants

Review: Everything but the independent
and dependent variable must be kept
constant.
 Constants:
other experimental factors
(potential variables) that stay the same
throughout experiment
 If many different things change at once, we
don’t know what causes the change!
Example

Let’s say we want to design an experiment to
determine what causes the Hornets to win games.
Number of
games that
Hornets win
Practice
You want to figure out which mosquito repellent is the
best. On 3 separate days, you apply a different
repellent and then go sit outside. You count the
number of bites you get each day.
IV =
Type of mosquito
repellent
DV =
Number of bites
Constants?
Practice

Maria wants to make the track team. She believes
that if she attends pre-season practice every day,
then she will be able to run fast enough to make the
team.
IV =
Frequency that
Maria attends
practice
DV =
Speed
Constants?
Practice

Students of different genders were given a Mickey
Mouse puzzle to assemble. The time it took each
group of students to assemble the puzzle was
measured.
IV =
Gender
DV =
Time to assemble
puzzle
Constants?
If the number of Higgins students
increases, then more school bus
drivers will be hired.
IV =
Number of students
DV =
Number of school
bus drivers hired
Constants?
What depends on what?
IV =
Amount of sugar used
DV =
Number of beignets
sold
Constants?
If the amount of sugar
used on beignets
decreases, then fewer
beignets will be sold.
If the Saints win more games this season, then they will
attract more big name players next season.
IV = Number of games won this
season
DV = Number of players attracted
next season
Constants?
Yesterday’s Exit Question

Let’s say you want to figure out what drink will
make you taller: milk, Gatorade, or water. You
drink each for a month and record your height at
the end of each month.
1. What is the independent variable?
2. What is the dependent variable?
3. What are at least two factors that should be held
constant?
HOMEWORK QUESTIONS?
Scenario 1

A researcher is studying the effect of sleep on
aggression, thinking that less sleep will lead to more
aggression. She has some people sleep 6 hours per
night, some people sleep 3 hours per night and
some people sleep as much as they want. She then
monitors aggressive behavior during basketball
games among participants.
 IV?
 DV?
 Constants?
Scenario 2

A researcher is curious to find out what effect classical music
has on people’s level of relaxation (as measured by heart
rate). He suspects that listening to classical music will make
people feel more calm and relaxed. He lets one group
listen to classical music for one hour. He lets another group
sit in a quiet room for one hour (i.e they hear no music).
After one hour, he monitors the heart rate of each
participant to measure their level of relaxation.



IV?
DV?
Constants?
Scenario 3

A researcher conducts an experiment to assess the effects of
alcohol on people's sense of balance. He divides his subjects
into three groups: in one group the participants drink one
ounce of alcohol, in another they drink two ounces of alcohol
and in a third group the participants drink soda. He then
watches as each participant tries to walk on a straight line
from one corner of the room to the next and notes how
many times they stumble outside the line.



IV?
DV?
Constants?
Unit 0 Domination Stats
Class Averages
nd
2
Period: 83.2%
rd
3 Period: 89.9%
th
5 Period: 91.5%
LAB SAFETY IS
ESSENTIAL!!!!!
Safety Equipment
Goggles
 Apron
 Gloves
 Fume hood
 Fire extinguisher
 Eye wash
 Safety shower

Safety Equipment

Goggles
Safety Equipment

Apron
Safety Equipment

Gloves
Safety Equipment

Fire extinguisher
Safety Equipment

Safety blanket
Safety Equipment

Eye wash
Safety Equipment

Safety shower
What could happen if we
don’t follow safety
guidelines?
Wear your safety goggles!
Chemical burn….
Frayed cord?
Unattended fire?
Safety
Contract
Lab Safety
Cartoon….
and a
Surprise!
Lab Safety Work Time



Read the Safety Contract thoroughly
Put one copy of the Safety Contract into the
“Culture and Goals” section of your binder
Take the other copy of the Safety Contract home;
a parent must read and sign it along with you
NEW NOTES:
PROCEDURES
Importance of a Good Procedure
We must read and follow directions all the time…
JUST THINK ABOUT DRIVING!
Importance of a Good Procedure
Key Point #1: Anyone can
understand and duplicate a good
procedure.
 Understand: The procedure is easy
to read and has simple language
 Duplicate: The procedure can be
repeated
When Things Go Wrong…
When Things Go Wrong…
Key Point #2: You must ALWAYS
have a plan while performing an
experiment.
This prevents problems
 It is important to always read ALL directions
and think before beginning an experiment

ANTICIPATION
How to plan a procedure….
Key Point #3: Characteristics of a
quality procedure…
1. Materials (including safety
equipment)
2. Step-by-step instructions
3. Each step is numbered
4. Specific and clear
Is this a quality procedure?
Is this a quality procedure?
Materials:
-Beaker
-Tongs
-Syringe
-Water
-Red dye
-Stirrer
Procedure:
Place the beaker on the lab bench. Pour 25 mL of water into
the beaker. Add 5 drops of red dye to the water and stir
with the stirrer. Heat the beaker up using a hot plate.
Is this a quality procedure?
Materials:
-Funnel
-Filter Paper
-Glass rod
-Erlenmeyer flask
-Water/sand mixture
Procedure:
1.
Place the filter paper in the funnel.
2.
Place the funnel in the Erlenmeyer flask.
3.
Use the glass rod to help pour the water/sand mixture into the funnel.
4.
Collect the filtrate in the Erlenmeyer flask.
5.
Clean up.
Exit Question
Select the materials and plan the
procedure to: (CHOOSE ONE)
make Kool-Aid
OR
make a sno-ball
Catalyst – January (6+1)2+6, 2012
FUN GRAPH FRIDAY! HW OUT!
1.
2.
Which
slime
increased
in price
the most?
Describe
how the
price of
Online
Vendor
slime has
changed
over time.
Today’s Agenda
Catalyst
 Quiz Stats and Return
 Lab Report How-To
 Plan Mystery Goo Lab
 Execute Mystery Goo Lab and Clean-Up
 Exit Question

Today’s Objectives
SWBAT write a lab report.
 SWBAT plan and execute an experiment to
test the following question:

 How
does the amount of corn starch added to 30 mL
of water AFFECT the thickness of the mystery goo?
 How does the type of corn starch added to 30 mL of
water AFFECT the thickness of the mystery goo?
Unit 0 Domination Stats
Class Grade Averages
nd
2
Period: 85.5%
rd
3 Period: 86.2%
th
5 Period: 82.7%
Unit 0 Domination Stats
As and Bs, 2nd Period
Jasmine B.
Luke
Nila
Jenna B.
Antoine
Jayson (100!)
Banika
Marlonika
Tra
Brionne
Jasmine G. (100!)
Chris
Deanna
Jorrance
Jevon
Jonathan
William
Kevin (100!)
Tirelle
Unit 0 Domination Stats
As and Bs, 3rd Period
Kevin
Mecalla
Ryan
Paul
Ryan
Layla
Demirr
Cory
Raymond
Josh
Joie
Jaymie (100!)
Kayla
Amber
Destiny
Allie
Lauren (100!)
Nick
Raven
Terrell
Simona
Unit 0 Domination Stats
As and Bs, 5th Period
Keiara
Jerome
Katherine
Taylor
Ashley
Kevin
Aerial
Molly
Jornell
Titus
Antione
Angel
Torien
Antoineka
Myjiel
LaNell
Champagne
Unit 0 Champs
1st Place (100): Jayson Camus, Jasmine
Gusman, Kevin Thomas, Jaymie Mayberry,
Lauren Smith
 2nd Place (99): Josh Hayes
rd
 3 Place (98): Deanna McCann

Lab Report

Goes through the Scientific Method (label each
section)
 Question
 Research/Background
Information
 Hypothesis
 Experimental
Design (IV, DV, Constants)
 Procedure
 Data
 Conclusion
 Future
Experiments/Citations
Question
How does the amount of corn starch
added to 30 of mL water affect the
thickness of the mystery goo?
OR
 How does the type of corn starch
added to 30 mL of water affect the
thickness of the mystery goo?

Background Information

Cornstarch is a fine, powdery starch that is made out of
corn. It is produced by grinding, washing and drying the
endosperm of the corn. Cornstarch has many culinary uses,
but it is most often used as a thickener for sauces, gravies
and fruit pie fillings. It has roughly twice the thickening
power of flour.
 16


ounce prices: Argo $1.28; Great Value $1.00
Mystery Goo acts like a solid and a liquid
Mystery Goo Recipe:
 30
mL water + 4 teaspoons cornstarch
Hypothesis
You com up with a QUALITY
hypothesis!
 Make sure you have a reason
(hint: use background info!)

Experimental Design
Independent Variable (IV): ?
 Dependent Variable (DV): ?
 Constants (at least 3): ???

Procedure

Materials
List
everything, including safety
equipment

Steps
Number
them
Available Materials

Corn starch
 Up
to 10 spoonfuls
total
Water
 Graduated cylinder

Up to 3 plastic cups
 1 bowl
 1 Plastic Spoon

 To
be reused
 Please don’t throw
away!
Exit Question

Write the steps of the scientific
method in order.