Defining Physical Science - Amazon S3Advances in Physical Science: Advances first stem from a need,...
Transcript of Defining Physical Science - Amazon S3Advances in Physical Science: Advances first stem from a need,...
Defining Physical Science
Defining Physical Science:
Physical Science:
The study of matter and energy
A merging of two major braches of Science:
1. Chemistry: Study of the composition
and changes of matter
2. Physics: Study of energy and laws of
motion (i.e. the behavior of matter)
Advances in Physical Science:
Advances first stem from a need,
followed by inquiry.
Science is the investigation of rational
concepts capable of being tested by
observation and experimentation.
This analytical method distinguishes
science from all other disciplines.
Advances in Physical Science:
Scientists: Question natural
phenomenon
Observe the world around them.
Read a variety of scientific books.
Become science teachers.
You are a scientist if you do any of these!
Advances in Physical Science:
Basic Assumptions of Science:
There is order in the universe.
The human mind is capable of
understanding it.
Natural phenomenon is testable by
experimentation that is repeatable.
A real Scientist will attempt to answer
their questions.
Scientific Method:
• The Scientific Method: A systematic
approach to problem solving.
1. State the problem: Must first define the
problem based on observation of a need.
2. Gather information on the problem: -- “
Leave no stones unturned”– The problem
may already be solved…at least partially.
Scientific Method:
3. Form A Hypothesis: A plausible prediction of the
outcome of experimenting.
- Use deductive reasoning (if/then statement)
- e.g. If I use a fuel additive in my car, then
it should improve its mileage.
- Hypothesis are often stated as a question.
Scientific Method:
4. Experiment: Test the Hypothesis
-Variable: One factor being tested.
-Data: Information outcome of the experiment.
Types of Data:
1. Quantitative: Numerical Data
2. Qualitative: Descriptive Data (color, behavior, etc)
Scientific Method:
Must use a control set-up and experimental set-up.
-The experimental set-up contains the
variable to be tested, the control does not.
-The control is the standard for comparison.
Scientific Method:
5. Record and Analyze data:
-Use Accurate Measurements
6. State Conclusions:
-Only after the experiment has been
repeated to insure accuracy.
Scientific Method: Theory:
The most logical explanation of events occuring in
nature.
Developed through repeated tests.
Law:
A repeatedly tested theory..
Generally accepted as true, but may be modified
after further discoveries.
Fact:
The absolute truth.
Scientific Method In Practice:
1. The problem: A need to lower the
freezing point of H2O to -10°C.
2. Information on the Problem:
-H2O freezes at 0°C
-Ethylene glycol freezes at -30°C
3. Hypothesis: One part ethylene glycol to
10 parts H2O will lower the freezing
point to -10°C.
Scientific Method In Practice:
4. Experiment:
Set up 6 replications of 1:10 ethylene glycol and
H2O mixtures.
Decrease Temperature.
Scientific Method In Practice: 5. Record and Analyze Data
Control: Experiment:
H2O C H2O w/ 1/10 Ethylene Glycol
0 -4
0 -3
0 -2
0 -3
0 -4
0 -2
X= 0 -3°C
Data or
Data Set
Scientific Method In Practice:
6. Conclusion: The freezing point of H2O
with 1/10 ethylene glycol is -3°C.
• Caution: Never test more than one
variable at a time.
• Use graphs to ease in interpreting data.
Time of Freezing of H2O with 1/10
Ethylene glycol (antifreeze)
Time (min) Temp °C
0 25
10 22
20 19
30 12
40 5
50 0
60 -3
-5
0
5
10
15
20
25
0 10 20 30 40 50 60
Time (min)
Te
mp
era
ture
(C
)
Temp
*Spaces between intervals on a graph must be equal.
Q: Does this graph represent the control or experimental set-up?
Scientific Terms:
Q: What does converge mean?
A: Come Together
Q: How would the temperature of a
reacting substance be affected in an
endothermic reaction?
A: Temperature would go opposite of
exothermic.
Scientific Measurements:
Measurements must be accurate,
reliable, and appropriate to the subject
measured.
Scientists use the metric or SI System
(Système International d’Unités).
Scientific Measurements:
Derived Units Volume: Liter
Weight: Newton
Density: Gram/Liter
Temperature: Celsius
SI Base Units
Scientific Measurements:
Length: Measure of distance
1 meter = 39.4 inches ( about 1 yard)
= 100 centimeters
= 1000 millimeteres
1000 meters = 1 kilometer
Common tools for measuring length
Meter Stick
Metric Ruler
Metric Tape
Rolotape
Scientific Measurements:
Prefix Symbol Multiplier Exponential
yotta Y 1,000,000,000,000,000,000,000,000 1024
zetta Z 1,000,000,000,000,000,000,000 1021
exa E 1,000,000,000,000,000,000 1018
peta P 1,000,000,000,000,000 1015
tera T 1,000,000,000,000 1012
giga G 1,000,000,000 109
mega M 1,000,000 106
kilo k 1,000 103
hecto h 100 102
deca da 10 101
1 100
deci d 0.1 10¯1
centi c 0.01 10¯2
milli m 0.001 10¯3
micro µ 0.000001 10¯6
nano n 0.000000001 10¯9
pico p 0.000000000001 10¯12
femto f 0.000000000000001 10¯15
atto a 0.000000000000000001 10¯18
zepto z 0.000000000000000000001 10¯21
yocto y 0.000000000000000000000001 10¯24
Metric prefixes, symbols, and multipliers
Scientific Measurments:
Volume: Amount of space an object takes up
Basic Unit: Liter (L) or Cubic Centimeter (cc or cm3)
Liters are usually used to measure liquid volume.
cm3 is usually used to measure solids.
○ e.g. The volume of a box can be measured by
length x width x heigth
○ 1 cm3 = 1 milliliter (1/1000 liter)
Scientific Measurments:
How could you measure the volume of an irregular shaped object in liters?
Liquid volume is measured using a graduated cylinder.
Measurements are read at the bottom of the meniscus (curved surface)
Bottom of Meniscus
Scientific Measurement:
Mass: The amount of matter in an object.
Basic Unit: Kilogram (1000 grams)
Mass is usually measured using a triple beam
balance.
Note: Mass is not the same as weight.
Scientific Measurements:
Density: The amount of mass in a given
volume of an object.
Density may be affected by:
1. Air trapped in the object.
2. Temperature of an object.
Scientific Measurements:
Density = Mass per unit volume of a
substance
Calculated by:
Density = mass divided by volume
Water density – 1 g/mL
d= m
V
Scientific Measurements:
Q: If wood floats in water, is its density
greater than or less than one?
Scientific Measurements:
Temperature: The amount of heat in an object
Basic Unit: Kelvin (K) Derived Unit: Celsius (C)
0 C = Freezing point of water
100 C = Boiling Point of water
Body Temp: 37 C
Room Temp: 21C
Measured using a thermometer (usually alcohol)
Scientific Measurements:
To convert temperatures:
K = C + 273
C = K -273
F = 9/5(C + 32)
C = 5/9(F − 32)
Dimensional Analysis:
Dimensional Analysis (DA): Method of
converting one unit to another
Uses a conversion factor- a factor that is
always equal to one
e.g. 1000 grams 1 or 1kilogram 1
1 kilogram 1000grams
Dimensional Analysis:
Convert 1350 grams to kilograms
1350 grams x 1 kilogram
1 1000grams
Cancel grams and multiply.
1350 x 1 kilogram = 1350 kg =1.35kg
1 1000 1000
Lab Safety:
Never do anything until you are
instructed.
Wear safety glasses in the lab when
you:
Use fire of any kind.
Handle hot glass.
Measure, mix or pour hot chemicals.