1. Chapter 1 Learning Objectives
•Distinguish Science from Technology
•Define Alchemy and Natural Philosophy
•Briefly describe the contributions of Bacon, Galileo, and Carson to the perceptions
of science.
•Define Hypothesis, Scientific Law, Scientific Theory, and Scientific Model, and
explain their relationships in science.
•Define Risk and Benefit, and give an example of each.
•Estimate a Desirability Quotient from benefit and risk data.
•Give an example of a use of Chemistry in your daily life and in society at large.
•Distinguish Basic Research from Applied Research.
•Differentiate: Mass & Weight; Physical & Chemical Change; Physical & Chemical
Properties.
•Classify matter according to state and as mixture, substance, compound, and/or
element.
•Assign proper units of measurements to observations and manipulate units in
conversions.
•Calculate the density, mass or volume of an object given the two other quantities.
•Distinguish between heat and temperature.
•Explain how the temperature scales are related.
•Use critical thinking to evaluate claims and statements.
2. Matter
• Science & Technology
• Matter
• Physical and Chemical Changes
• Pure Substances
• Mixtures
3. A Science for All Seasons
Chemistry is the study of matter and its changes.
Everything we do involves chemistry.
4. Science & Technology
July 8, 2011
Space Shuttle Atlantis lifts off from Launch Pad 39B at
Kennedy Space Center, FL. Squid in Space are on Board!!
Photo Credit NASA
See the launch: http://www.youtube.com/watch?v=tqrDWa7Eabk
5. What is Matter?
• Everything that has mass and volume is
called matter.
Water is present in three phases…name ‘em!
6. Green and Sustainable Chemistry
Green chemistry uses materials and processes that
are intended to prevent or reduce pollution at its
source.
Sustainable chemistry is designed to meet the needs
of the present generation without compromising the
needs of future generations.
7. Science
Science has five characteristics. Science is
• Testable
• Reproducible
• Explanatory
• Predictive
• Tentative
8. Science
Scientific models are tangible items or pictures used
to represent invisible processes.
Elena O'Brien, scientific support
rep for antibody maker Abcam,
shows the new look for leather still
sexy, now office-appropriate .
Who are these guys? What are they looking at?
So which one is a scientific
model? ..really?
9. Molecular Modeling
Molecules are groups of two or more atoms held
together by chemical bonds.
Molecular models are three-dimensional
representations of molecules.
Check this out:http://jmol.sourceforge.net/
10. Changes in Latitude…
Changes in Matter…
• All matter,
regardless of state,
undergoes
physical and
chemical changes.
• These changes can be
microscopic or
macroscopic.
12. What is a Physical Change?
• A physical change occurs when the
substance changes state but does not
change its chemical composition.
• The form or appearance has changed,
but the properties of that substance are
the same (i.e. it has the same melting
point, boiling point, chemical
composition, etc.)
13. Physical Change: Examples
• Dry Ice is Sublime…. http://www.youtube.com/watch?
v=W3PkuaYYOtg&feature=related
• Others: cutting a piece of wood into smaller pieces, etc. Watch this…
http://www.youtube.com/watch?v=fy81xU6vBC8
14. Chemical Changes:
• A chemical change occurs when a substance
changes into something new. This occurs due
to heating, chemical reaction, etc.
• You can tell a chemical change has occurred if
the density, melting point or freezing point of
the original substance changes.
• Many common signs of a chemical change can
be seen (bubbles forming, mass changed, etc).
• I love Bill Nye…
• http://www.youtube.com/watch?v=5BF4We7qMf0&feature=related
15. • Reaction with acids • Ability to act as
• Reaction with bases reducing agent
(alkalis) • Reaction with other
• Reaction with oxygen elements
(combustion) • Decomposition into
• Ability to act as simpler substances
oxidizing agent • Corrosion
17. • Physical and chemical properties may be
intensive or extensive.
• Better check this out…
http://www.youtube.com/watch?
v=m0IH3Hgy3oI&feature=related
18. • Intensive properties such as density, color,
and boiling point do not depend on the
amount of the sample of matter and can be
used to identify substances.
20. • Physical properties are those that we can
determine without changing the identity of
the substance we are studying.
21. • The physical properties of sodium metal can
be observed or measured. It is a soft,
lustrous, silver-colored metal with a
relatively low melting point and low
density.
• Hardness, color, melting point and density
are all physical properties.
22. • Chemical properties describe the way a
substance can change or react to form other
substances. These properties, then, must be
determined using a process that changes the
identity of the substance of interest.
23. • One of the chemical properties of alkali
metals such as sodium and potassium is that
they react with water. To determine this,
we would have to combine an alkali metal
with water and observe what happens.
• This is nutz: http://www.youtube.com/watch?
v=m55kgyApYrY
• In other words, we have to define chemical
properties of a substance by the chemical
changes it undergoes.
24.
25. Matter is identified as either a….
• Pure Substance: Element or
Compound,
or a….
• Mixture: Homogeneous Mixture
or Heterogeneous Mixture
26. • Can a pure substance be further
broken down or purified by physical
means? (Give examples)
• Does each pure substance have its
own characteristic properties that are
different from the set of properties of
any other pure substance? (Give
examples)
27. • Do PS have constant composition?
• Can PS be changed in identity and
properties by chemical methods?
• Do PS have constant properties?
28. Mixtures are two or more pure substances that
are NOT chemically combined.
•Do mixtures have constant boiling points?
•Do mixtures have constant melting points?
29. Compounds Elements
• Can be decomposed • Cannot be
into simpler decomposed into
substances by simpler substances by
chemical changes, chemical changes
always in a definite • Atoms?
ratio
• Molecules?
31. • Variable composition
• Components retain their characteristic
properties
• May be separated into pure substances by
physical methods
• Mixtures of different compositions may
have widely different properties
32. Homogenous mixtures look the same
throughout but can be separated by
physical means (dissolution, centrifuge,
gravimetric filtering, etc.). Examples:
milk, yogurt
33. • Solutions are homogenous mixtures
that do not scatter light.
• These homogeneous mixtures are
created when something is completely
dissolved in pure water.
•They are easily separated by
distillation or evaporation.
Examples: sugar water, salt water
34. • Heterogeneous mixtures are composed of
large pieces that are easily separated by
physical means (ie. density, polarity,
metallic properties).
• Examples?
35. • Do not have same
composition
throughout
• Components are
distinguishable
Examples: fruit
salad, vegetable
soup, etc.
37. (And how the Kinetic Molecular
Theory affects each)
•Solids
•Liquids
•Gases
•Plasma
38.
39. •Have a definite shape
•Have a definite volume
Kinetic Molecular Theory
Molecules are held close together
and there is very little movement
between them.
40. •Have an indefinite shape
•Have a definite volume
Kinetic Molecular Theory:
Atoms and molecules have more
space between them than a solid
does, but less than a gas (ie. It is
more “fluid”.)
41. •Have an indefinite shape
•Have an indefinite volume
Kinetic Molecular Theory:
Molecules are moving in random
patterns with varying amounts of
distance between the particles.
42. At 100°C, water
Below 0°C, water becomes water
solidifies to become vapor, a gas.
ice. In the solid state, Molecules can
water molecules are move randomly
held together in a over large
rigid structure. distances.
Between 0°C and 100
°C, water is a liquid.
In the liquid state,
water molecules are
close together, but
can move about
freely.
43. Changing states requires energy in either
the form of heat. Changing states may also
be due to the change in pressure in a
system.
Heat of vaporization, Hv Heat of formation, Hf.
44. • Plasma is by far the most common form of matter.
• Plasma in the stars and in the tenuous space between
them makes up over 99% of the visible universe and
perhaps most of that which is not visible.
• Plasma is a high energy electrically charged mixture
of ions and electrons. While plasma is the most
abundant phase of matter in the universe, on earth it
only occurs in a few limited places. Plasma appears
on earth only in places like lightning bolts, flames,
auroras, and fluorescent lights.
45. On earth we live upon an island of "ordinary" matter. The
different states of matter generally found on earth are
solid, liquid, and gas. We have learned to work, play, and
rest using these familiar states of matter. Sir William
Crooke's, an English physicist, identified a fourth state of
matter, now called plasma, in 1879. Plasma temperatures
and densities range from relatively cool and tenuous (like
aurora) to very hot and dense (like the central core of a
star). Ordinary solids, liquids, and gases are both
electrically neutral and too cool or dense to be in a
plasma state.
The word "PLASMA" was first applied to ionized gas by
Dr. Irving Langmuir, an American chemist and physicist,
in 1929.
46. Star formation in the
Eagle Nebula
Space Telescope Science
Institute, NASA
(below) (Above)
X-ray view of
Sun
from Yohkoh,
ISAS and NASA
48. Laser plasma interaction during inertial
confinement fusion test at the
University of Rochester.
49. Both inertial and magnetic confinement fusion research
have focused on confinement and heating processes with
dramatic results. The next stage of operating power
reactors will produce about 1 GW of power and operate
at 120 million degrees Kelvin.
50. Plasma consists of a collection of free-
moving electrons and ions - atoms that
have lost electrons. Energy is needed to
strip electrons from atoms to make plasma.
The energy can be of various origins:
thermal, electrical, or light (ultraviolet
light or intense visible light from a laser).
With insufficient sustaining power,
plasmas recombine into neutral gas.
51. Plasma can be accelerated and steered by
electric and magnetic fields which allows
it to be controlled and applied. Plasma
research is yielding a greater
understanding of the universe. It also
provides many practical uses: new
manufacturing techniques, consumer
products, and the prospect of abundant
energy.
53. EXAMPLES:
•Printing on plastic food
•Computer chips and containers
integrated circuits
•Energy-efficient window
•Computer hard drives coatings
•Electronics •High-efficiency window
•Machine tools coatings
•Medical implants and •Safe drinking water
prosthetics •Voice and data
•Audio and video tapes communications components
•Aircraft and automobile •Anti-scratch and anti-glare
engine parts coatings on eyeglasses and
other optics
54. Plasma technologies
are important in •Waste processing
industries with annual
world markets •Coatings and films
approaching $200 •Electronics
billion
•Computer chips and
integrated circuits
•Advanced materials
(e.g., ceramics)
•High-efficiency
lighting
55. Water
Purification Plasma-based sources
Systems can emit intense beams
of UV & X ray radiation
or electron beams for a
variety of environmental
applications.
56. For water sterilization, intense UV emission
disables the DNA of microorganisms in the
water which then cannot replicate. There is
no effect on taste or smell of the water and
the technique only takes about 12 seconds.
57. This plasma-based UV method is effective
against all water-born bacteria and viruses.
Intense UV water purification systems are
especially relevant to the needs of
developing countries because they can be
made simple to use and have low
maintenance, high throughput and low
cost. Plasma-based UV water treatment
systems use about 20,000 times less energy
than boiling water!
58. •There is no observable change in the
quantity of matter during a chemical
reaction or a physical change.
•In other words, matter cannot be
created nor destroyed. It is just
converted from one form to another
61. Density
Density is defined as the
amount of matter in a given
amount of space.
d = m/V
The density of copper is
8.94 g/cm3.
62. Density: Practice Problem
Calculate the density of a metal sample with a mass
of 18.96 g and a volume of 4.31 cm3.
d = m/V
= 18.96 g/4.31cm3
= 4.40 g/cm3
63. Numbers in Chemistry:
Accuracy & Precision
• Why Measure? CO2?
Heat? O3? Radiation?
Fossil Fuels? Hydrogen
Economy?
• Exact Numbers vs.
Measurements…What’s
the difference?
64. A Visit from Ironman…or is that “Fe”-man?
• Ironman knows how to measure
things with great accuracy
• In Class Activity: L, W, T of
your Chemistry text! Volume?
• Were you precise?
• Accurate?
• Both?
• How do you know?
• What is a “true value”, AKA
“accepted value”?
65. A Game of Chance? Skill?
• What’s best? Accuracy or Precision?
• How can this objective be achieved in science?
• Does this connect to the lab? How?
66. Are You Sure You Are Uncertain?
• What’s the difference
between these two
pictures?
• Whys does it matter to
me?
• Which measuring
instrument is better?
• What makes it better?
• Hmmm…uncertainty?
67. Instrument Uncertainty
• OK ± What? Why?
• Certainty vs. an estimated digit on
a measuring instrument
• Obtain a measuring instrument
from lab & explain to partner
Mr. Tyler & Mr. Bean give extra help to a
Chemistry student. (Which one is “Beaker”?)
what the estimated digit in a
measurement has to do with
uncertainty.
Test Your Knowledge!!
1) What is the instrument uncertainty for the 100 mL
graduated cylinders we use in lab?
2) What is the instrument uncertainty for the 100 mL
beakers we use in the lab?
68. Significant Figures Rule!!!
There are three rules on determining how many significant figures are in a
number:
1. Non-zero digits are always significant.
2. Any zeros between two significant digits are significant.
3. A final zero or trailing zeros in the decimal portion
ONLY are significant.
• Focus on these rules and learn them well. They will be used
extensively throughout the remainder of this course. You
would be well advised to do as many problems as needed to
nail the concept of significant figures down tight and then do
some more, just to be sure.
• Please remember that, in science, all numbers are based upon
measurements (except for a very few that are defined). Since all
measurements are uncertain, we must only use those numbers that
are meaningful. A common ruler cannot measure something to be
22.4072643 cm long. Not all of the digits have meaning
(significance) and, therefore, should not be written down. In science,
only the numbers that have significance (derived from measurement)
are written.
69. Significant Figures…The Rules in More Detail
Significant figures
a) All non-zero digits are significant e.g. 1.234 has 4 significant figures. The information
conveyed by the digits is that there is one unit, 2 numbers of 0.1mm, 3 numbers of 0.01 mm
and 4 numbers of 0.001 mm. Therefore each digit conveys specific information regarding that
place value.
b) Zeroes between non-zero digits are significant e.g. 12.004 has 5 significant figures The two
zeroes in the value convey the information that there are zero numbers of 0.1mm and zero
numbers of 0.01 mm. Note that there is significant information about smaller units and larger
ones.
c) At the end of a number all zeroes are significant, even after the decimal point e.g. 9.100 has 4
significant figures The two zeroes are specifically conveying the information that there are
zero numbers of 0.01 mm and zero numbers of 0.001 mm.
d) At the end of a number all zeroes are usually significant if before the decimal point. e.g. 4000
has four significant figures, This implies that the digit filling the units place is not definitely
known
e) Zeroes which merely assign place value to a non zero digit are not significant. e.g. If 4000 is
correct to the nearest ten, it has only three significant figures. This implies that the digit filling
the units place is not definitely known and if 4000 is correct to the nearest hundred it has 2
significant figures. This implies that the digit filling the units place and the tens place are not
definitely known. e.g. when the population of a country is said to be 900,000,000 the figure is
probably correct to the nearest 100 million. Thus there are 9 units of size 10 8 units. That is to
say, this number has just one significant figure, even though there are nine digits reported.
f) Zeroes reported at the beginning of a number before or after the decimal point are always non-
significant. These are also placeholder zeroes. 007 metre = 7 x 10o m ............................1 sig.
fig.
0.007 metre = 7 x 10-3 m ...........................1 sig. fig.
0.070 metre = 7.0 x 10-2 m.........................2 sig. fig.
70. Significant Figures &
Measurement
• Sig Fig’s are BASED on measurements.
• The number of Sig Fig’s you report in a
measurement depends on the ACCURACY
of the measuring device.
71. Hmm…What’s a Derived Unit??
• Density
• How do you calculate
density?
• Do you need to make
measurements? How
many?
• How could you
calculate the density of
air at sea level?
• What is a hematocrit?
72. Energy: Heat and Temperature
Energy is the ability to do work or transfer heat.
Energy exists in two major forms:
• Potential energy is stored energy.
• Kinetic energy is energy in motion.
73. Heat vs. Temperature
What is the difference between Heat &
Temperature?
Heat is energy that is transferred from hotter objects
to cooler objects.
Temperature is the average kinetic energy of the
atoms or molecules that make up an object.
75. Units of Heat
Heat energy is often measured in calories or joules.
• One calorie (cal) is the amount of heat required to
change the temperature of 1.00 g of water 1.00 oC.
• A calorie is 4.184 joules (J).
1 cal = 4.184 J
76. Food Calories
A food calorie (Cal, “C” is capitalized) is actually a
kilocalorie.
1 Cal = 1 kcal = 1000 cal = 4184 J
77. Energy
• What is energy?
• What units quantify energy?
(cal, Cal, Joule?)
James Prescott Joule
• What is a calorie? A Calorie?
…a joule?
• Law of Conservation of
Energy?
• SH H2O = 4.184joules/g•oC
Hmm..what’s more energy? Cal or cal?
78. Physical Properties of Water
• USGS Site:
http://ga.water.usgs.gov/edu/waterproperties.html
1) Explain why water is considered an excellent
thermal buffer and why this is ecologically
significant.
2) Water has it’s maximum density at 4oC, not 0oC.
Explain why this occurs and how it is
ecologically significant.
79. Unit Analysis, Factor-Label Method,
Dimensional Analysis, Bridge
Building…..all synonyms!
• "I thought I knew everything and that speech was the only thing that
mattered in high school. When Mr. Bean taught our Chemistry class unit
analysis, I didn't care about it at all. I was making plans for the weekend
with my girlfriend who loved me because I was a speech team stud with
offers from Brown, Princeton and Harvard and not because of Chemistry.
While my homies were home solving unit analysis problems, I was
practicing a speech. Then one day I was hit hard at a speech tournament.
Splat…no mo swag. I totally clutched on my speech, no points, zippo. I was
despondent. My girl friend dumped me. My parents, who used to brag
about my speech stats, started getting on my case about my grades. I
decided to throw myself into my school work. But I couldn't understand
anything. I would get wrong answers all of the time. I now realize that my
failure in school came from never having learned unit analysis. I finally
decided to learn unit analysis. After three hours of studying unit analysis I
get it. My swag is back. My speechie homies are chillin’. Last weekend I
placed first in the speech tournament. My girlfriend came back to me and
my parents are off my case.” Jeff
80. What's the Method? Unit Analysis
Example 1: This is a structured way of helping you to convert units. With this method, you can easily and
automatically convert very complex units if you have the conversion formulas. The method involves the
following steps
Example: Convert 6.0 cm to km
1. Write the term to be converted, (both number and unit) 6.0 cm
2. Write the conversion formula's 100 cm = .00100 km
3. Make a fraction of the conversion formula, such that…..
a) if the unit in step 1 is in the numerator, that same unit in step 3 must be in the denominator.
b) if the unit in step 1 is in the denominator, that same unit in step 3 must be in the numerator.
Since the numerator and denominator are equal, the fraction must equal
6.0 cm .00100 km
100 cm
4. Multiply the term in step 1 by the fraction in step 3.
5. Perform the indicated calculation rounding the answer to the correct number of significant figures. 0.000060
km or 6.0 E -5 km
81. ..and finally…everybody and
mean everbody talks…about
sigfigs!
• http://www.youtube.com/watch?
v=X5G9tIe84lE&feature=related
• ..and from my generation…a little Dixie
Chicken:
• http://www.youtube.com/watch?v=3z-
GwdaKrn8&feature=related
Notes de l'éditeur
Basic definition of matter.
Definition of physical changes.
Chemical Changes are characterized by the following:
Definition of a substance.
Basic characteristics of pure substance:
The two categories of pure chemical substances.
Basic identification of a mixture.
Brainstorm more examples of heterogenous mixtures.
