CHAPTER
ONE
SCIENCE SKILLS
WHAT IS SCIENCE?
It is a knowledge and the process
that gets us to that knowledge.
If it begins with curiosity- it ends
in discovery.
The fun part of science is that you
don’t know what you will find.
*
Curiosity provides questions.
Methods such as observing
and measuring provide ways
to find answers.
WHAT IS
TECHNOLOGY?
It improves people’s lives . The use of
knowledge (science) to solve practical
problems.
Advances in one lead to advances in
the other (interdependent)
*
The goal of science is to expand
knowledge. The goal of
technology is to apply that
knowledge.
LAB REVIEW
Inquiry Activity P. 1- How do scientist use their observations/
Solution: CuCl2
Copper(II) chloride + Aluminum →Copper +Aluminum chloride
A single replacement reaction is what
occurred in the lab.
The aluminum replaced the copper in
the solution.
SECTION 1.1 INTEREST
GRABBER (JOURNAL ENTRY)
Science improves our Quality of Life.
Advances in science have led to devices that
make our lives easier and more pleasant. For
example, the microwave oven makes it
possible to prepare meals and snacks in
minutes rather than hours.
1. Name five household devices that make
your life easier or more pleasant.
2. Go through your list and describe how
each device's function was accomplished
before its invention.
BRANCHES OF
SCIENCE
The study of science is broken
down into social sciences and
natural science.
Natural science is usually divided
into 3 branches.
1: PHYSICAL SCIENCE
Focus on non-living things
A. Physics-The study of
matter and energy and the
interactions between the
two through forces and
motion
B. Chemistry- The study of
composition, structure,
properties, and reactions of
matter.
2: EARTH AND SPACE
SCIENCE
A. Geology-(Earth science)The
study of the origin, history, and
structure of Earth.
B. Astronomy-(Space science)
The study of the universe beyond
Earth, including the sun, moon,
planets, and stars.
3: LIFE SCIENCE
The study of living things.
A. Biology- The study of life
and life processes.
SECTION 1.2 USING A
SCIENTIFIC APPROACH
Scientific Method- An organized
plan for gathering information.
Goal- to solve a problem or to
better understand an observed
event.
STEPS TO THE
SCIENTIFIC METHOD
Make an observation
Ask a question
Develop a hypothesis
Test hypothesis with an experiment
Test with more experiments
Revise hypothesis
Analyze data and draw conclusions
Hypothesis is supported
Develop a theory
Hypothesis is not supported
*
1. Observation- information that you
gain through your senses.
- Repeatable observations are known
as facts.
2. Hypothesis- is a proposed answer
to a question.
- has to be testable
- can be an if, than statements.
*
3. Experiments- used to test hypothesis.
- Any factor that can change in an
experiment us called a variable.
- Manipulated variable- the variable that
causes a change in another variable.
- Responding variable- the variable that
changes in response to the
manipulated variable.
*
A controlled experiment is an experiment in
which only one variable, the manipulated
variable, is deliberately changed at a time.
- It exams the relationship between the
manipulated and responding variables.
- Controlled variables- all variables being
held constant.
*
4. Analyze data and draw conclusions
Based on the data produced by an experiment,
scientists can draw a conclusion about
whether the evidence supports or disproves
the hypothesis.
Once a hypothesis has been supported in
repeated experiments, scientists can begin to
develop a theory.
A scientific theory -is a well-tested explanation
for a set of observations or experimental
results.
*
Theories are never proved.
- They may be revised or replaced.
Scientific law- A statement that summarizes a
pattern found in nature.
* A scientific law describes an observed
pattern in nature without attempting to
explain it. The explanation of such a pattern
is provided by a scientific theory.
*
A model is a representation of an object or
event.
Scientific models make it easier to
understand things that might be too
difficult to observe directly.
Communication- this is done throughout
the process.
SAFETY IN THE LAB
Whenever you work in your science
laboratory, it’s important to follow
safety precautions at all times.
Always follow your teacher’s
instructions and the textbook
directions exactly.
SECTION 1.3
MEASUREMENT
• Scientist often work with very large or very small
numbers.
• Instead of writing out all the zeroes in such
numbers, you can use a shortcut called
scientific notation.
• Scientific, notation is a way of expressing a
value as a product of a number between 1 and
10 and a power of 10.
• For example, the number 300,000,000 written in
scientific notation is 3.0 x 10 8
• Using scientific notation makes very large or
very small numbers easier to work with.
SI UNITS
Scientists use a set of measuring units
called SI, or the International System of
Units.
SI is built on seven metric units, know as
base units.
*
1. The meter [m] for length
2. The kilogram [kg] for mass
3. The kelvin[K] for temperature
4. The second[s] for time
5. The mole [mol] for amount of substance
6. The ampere [A] for electric current
7. The candela [cd] for luminous intensity
*
Additional SI units, including volume and
density, are derived units.
Derived units are made from combinations
of base units.
Density- is the ratio of an object’s mass to
its volume.
Density= Mass
Volume
= M
V
units are g/L
METRIC PREFIXES
The unit for a given quantity is not always a
convenient one to use.
The measurement can be written in a more
compact way using a metric prefix.
A metric prefix indicates how many times a
unit should be multiplied or divided by 10.
Chart on page 17
FACTOR LABEL
METHOD
Easiest way to convert from one unit
of measurement to another is to use
conversion factors.
Example: kilograms to pounds
- Use the conversion 2.1kg = 1lb
-It is a ratio of equivalent
measurements that is used to convert
a quantity from one unit to another.
LIMITS OF MEASUREMENTS
Precision is an assessment of how exact a
measurement is.
Significant figures are all the digits that are known
in a measurement, plus the last digit that is
estimated.
The fewer the significant figures, the less precise
the measurement is.
The precision of a calculated answer is limited by
the least precise measurement used in the
calculation.
Another important quality of measurement is
accuracy, which is the closeness of a measurement
to actual value of what is being measured.
RULES FOR
SIGNATURE FIGURES
1) Digits other than 0 are always significant
Example
96 = 2 significant numbers
0.52 = 2 significant numbers
RULES FOR
SIGNATURE FIGURES
2) 1 or more final zeros used after the decimal point are
always significant.
Example
4.00= 3 significant figures - it is an exact measurement.
0.520 = 3 significant figures (sig Figs)
RULES FOR
SIGNATURE FIGURES
3)Zeros between two other significant figures (numbers) are
always significant.
Example
204 = 3 sig figs.
10.06 = 4 sig figs.
3.040 = 4 sig figs
RULES FOR
SIGNATURE FIGURES
4) Zeros used solely for spacing the decimal point are not
significant. These zero’s are called place holders
Example
400 = 1 sig fig
400. = 3 sig fig
0.002 = 1 sig fig
SIGNIFICANT FIGURES IN
CALCULATIONS
Addition and Subtraction
The answer can only have the same
number of digits as the measurement with
the least number of digits to the right of the
decimal place.
*
Examples:
Addition
6.43
+2.015
8.445 = 8.44
Subtraction
213.67
 98
115.67 =116
SIGNIFICANT FIGURES IN
CALCULATIONS
Multiplication and Division
The answer can have only the same
amount of significant figures as the
measurement with the least number of
significant figures.
*
Examples:
Multiplication
Division
12.0 3 sig. figs
2.50  0.04 = 62.5
4.3 2 sig. figs
51.6 = 52 answer 2 sig. figs
3
1= 1
answer 60
1 sig. fig
TEMPERATURE
CONVERSIONS
• We use Kelvin (K) for SI unit
• Do not use a degree mark () before the
K.
• We use Celsius (C) for metric system
• We use Fahrenheit (F) in the United
States
TEMPERATURE
CONVERSIONS
Conversion Examples:
Formula
Example
C + 273.15 = K
25C + 273.15 = 298.15 K
K – 273.15 = C
315.00 – 273.15 = 41.85C
TEMPERATURE
CONVERSIONS
Formula
Example
F = 9/5 C + 32
F = 9/5 28C + 32 = 82F
C = 5/9(F – 32)
C = 5/9(77F –32) = 25C
9/5 = 1.8
5/9 = 0.55