UNIT 1: Activities in
Science
science
scientific method
observation
inference
classification
hypothesis
experiment
independent variable
dependent variable
control
conclusion
theory
scientific law
qualitative data
quantitative data
chemistry
matter
mass
weight
inertia
energy
potential energy
kinetic energy
British system
Metric system
SI system
kelvin
derived units
natural units
base unit
second
meter
kilogram
Objectives
•Identify the common steps of scientific methods.
•Compare and contrast types of data.
•Identify types of variables.
•Describe the difference between a theory and a
scientific law.
Describe the different parts of an experiment.
Express how an experiment can be improved.
Compare and solve problems using System
International units and derived units
Identify the different types of properties
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Scientists use scientific methods to systematically
pose and test solutions to questions and assess
the results of the tests.
The scientific method is a organized, systematic
process used by scientists to do research in
scientific study, whether it is chemistry, physics,
biology, or another science and provides methods
for scientists to verify the work of others.
A complete description of methods is necessary so
that other scientists can repeat the same methods.
Repeating the method should produce similar
results; if not the results of the original experiment
may be questioned.
• The steps in a scientific method are
repeated until a hypothesis is accepted
or discarded.
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An observation is the act of gathering
information through your senses and
depends upon what you already know,
must be repeated by more than one
person.
Qualitative data is obtained through
observations such as hot, cold, color,
odor, presence of bubble, or some other
physical characteristic that is related to
the five senses.
Quantitative data indicates “how much”:
what is the specific temperature, volume,
mass or some other information needed
by the experimenter.
• Inference - interpretation of an
observation
• Classification - is done by looking for
regularities between objects
• Hypothesis - educated guess or
temporary observation for an observed
regularity which can can never be
proven or disproved, only supported or
not supported.
• Conclusion - judgement reached by
reasoning
• Theory - a verified hypothesis
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Experiment - Set of controlled observations that test
the hypothesis or proposed explanation
•Must be set up carefully in order to change and test
only one variable at a time
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Independent variable – the thing the scientist is
testing the effect of (changes)
Dependent variable – the thing the scientist
measures
•Dependent on the independent variable
Constant – factor that is not allowed to change during
the experiment
Control – standard for comparison, does not receive
the independent variable
Class Work Assignment:
Experimental Design With The Simpsons
For each exercise, please determine
The
Control Group
The Independent Variable
The Dependent Variable
What should the conclusion be?
How Could the Experiment Be Improved?
Waylon Smithers
Smithers
Group
A
Number of
Stapled
Papers
1,587
B
2,113
thinks that a special
juice will increase the productivity
of his workers.
He creates two groups of 50
workers each and assigns them
the same task, stapling sets of
papers.
Group A is given the special juice
to drink while they work.
Group B is not given the special
juice.
After an hour, he counts how
many stacks of papers each
group has made.
Homer Simpson
Homer
notices that his shower is covered
in a strange green slime.
His friend Barney tells him that coconut
juice will get rid of the green slime.
Homer decides to check this out by
spraying half the shower with coconut
juice and the other half with water.
After three days of “treatment” there is no
change in the appearance of the green
slime on either side of the shower.
Bart Simpson
Bart
believes that mice exposed to microwaves will
become extra strong
He placed 10 mice in a microwave for 10 seconds.
He compared these to another 10 mice that had not
been exposed by placing a block of heavy wood in
front of their food.
Could move Mice Could not
block
Group
move
block
Exposed to
8
2
Microwaves
Not Exposed
7
3
Krusty the Clown
Krusty
Subject A
Old Powder 30 minutes
of itching
Subject B
New Powder 45 minutes of
itching
was told that a
certain itching powder was
the newest best thing on
the market, causing 50%
longer lasting itches. He
buys the new powder and
compares it to his old
powder by testing the two
products on two different
subjects
Design an experiment for Lisa Simpson
Describe
Lisa
Simpson is working
on her science project:
“Does Rogooti (a
commercial hair product)
affect the speed of hair
growth?” Her family is
willing to volunteer for the
experiment.
how Lisa would
perform this experiment
Identify the control group
and the independent and
dependent variables
• Chemistry and Matter
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Everything around you is matter
Chemists study matter
Conclusion:
Matter - is anything that has mass and occupies space
is neither created nor destroyed in ordinary
chemical reactions, this is called the LAW OF
CONSERVATION
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Weight - the amount of matter in an object and the effect of
gravity on that matter
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What happens to your weight if you go to the moon?
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What happens to your mass if you go to the moon?
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Mass - is what gives an object it's property of weight and
it's inertia
Inertia - the property in matter which causes it to resist
change in motion
matter exists in several forms: solid, liquid, gas and
plasma, which is a gas composed of charged particles
Energy - the ability to do work
When matter changes from one form, energy is conserved
Potential Energy - stored energy, energy due to position or
composition
Kinetic Energy - energy of motion 1/2 (mass) (velocity)2
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Measurement
Measurements - are comparisons to some standards
use a number + units
Metric Units (SI Units)
9 fundamental quantities
length -
meter -
mass time temperature -
kilogram second kelvin -
amount of substance -
mole -
luminous intensity -
candela
electric current -
m
s
K
mol
-
Amphere -
plane angles
radian -
solid angles
steradian - sr
kg
cd
A
rad
• The SI base unit of time is the second (s),
based on the frequency of radiation given off
by a cesium-133 atom.
• The SI base unit for length is the meter (m), the
distance light travels in a vacuum in
1/299,792,458th of a second.
The meter is a little longer than a yard.
• The SI base unit of mass is the kilogram (kg),
about 2.2 lbs.
• The SI base unit of temperature is
the Kelvin(K).
• Zero kelvin is the point where there
is virtually no particle motion or
kinetic energy, also known as
absolute zero.
• Two other temperature scales are
Celsius and Fahrenheit.
T-Scale
106
M
103
102
101
10-1
k
h da m
d
g
L
s
10-2
10-3
10-6
c m
µ
Prefix Abbreviation Multiplicative Amount * The letter μ is the Greek
letter lowercase equivalent to an m and is called “mu” (pronounced “myoo”).
Prefix
Symbol
Factor
giga
G
1,000,000,000
mega
M
Sci Notation
10E9
1,000,000
Example
gigameter (Gm)
10E6
kilo
k
1,000
deci
d
1/10
centi
c
1/100
10E-2
centimeter (cm)
milli
m
1/1000
10E-3
milligram (mg)
micro
µ
10E3
megagram (Mg)
10E-1 deciliter (dL)
1/1000000
nano
n
1/1000000000
pico
p
1/1000000000000
kilometer (km)
10E-6
10E-9
microgram (µg)
nanometer (nm)
10E-12
picometer (pm)
32˚Fahrenheit
0˚C
273.15 Kelvin
• Conversion Factor Method
• Given (# + UNIT) x
• ratios of equal quantities...
• Example:
• Unitary Rates -
- a ratio equal to one with a
denominator of one
• Unitary Rate examples:
• ?cm = 1.5m x 100cm/1m = 150 cm
• ?km = 4280m x 1 km/1000m = 4.280km
• ?µm = .018 km x 10E3m/1km x 10E6µ/1m = 1.8 x
10E7µm
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= (1.8 x 10E-2)
• Non-unitary Rate ex:
• ?m/s =92km/h x 1000m/1m x 1k/3600s x
72,000m/3600s x 20m/1s =
• Many physical phenomena are measured in
units that are derived from SI units.
• A unit that is defined by a combination of base
units is called a derived unit.
several quantities together - areas, volumes
• ? cm2 = 1 m2
• 100 cm = 1 m
• (100 cm)2 = (1 m)2
• 10,000 cm2 = 1 m
Volume is measured in cubic meters (m3), but this
is very large, about the size of a washing machine.
A more convenient measure is the liter, or one
cubic decimeter (dm3).
Density
extensive property depends upon the amount of matter
being measured. ex. mass, volume
intensive property does not depend upon the amount of
matter being measured. ex. color, smell, density, taste
Density is a derived unit, g/cm2, the amount of mass
per unit volume.
Density is a measure of how much matter is packed into
a certain space.
The density equation is density = mass / volume.
• 133g of gold has a volume of 6.90 cm3
• density 133g / 6.90 cm3 = 19.3 g/cm3
• What is the mass of 3.0 ml of ether? (d = 0.70
g/mL
• ?g = 3.0mL x 70g / 1mL = 2.1 g
• What volume does 48g of CCl4 have (d =
1.59g/mL)
• ?mL = 48g x 1 mL / 1.59g =30.mL