Topics to be Covered
• Physical & Chemical Properties
• Intrinsic v. Extrinsic Properties
• Physical and Chemical Changes
• Pure Substances
• Mixtures
• States of Matter
1. Physical properties
• How the item looks,
smells, behaves when it is
not changing its identity.
• (Examples on next slide)
2. Chemical properties
• Can only be observed when a chemical
change occurs.
• Explain how reactive it is.
• What it reacts with.
Intrinsic v. Extrinsic Properties
Intrinsic • Also called “intensive”
• Ex: density,
conductivity, reactivity
• Do not change with the
amount of material
being measured.
• also called extensive
• Ex: volume and mass
• change with the amount
of material being
measured
Extrinsic
• What we observe macroscopically (smell,
bubbles forming, color changes,
combustion)
• indicates what is happening
microscopically (breaking and forming of
bonds between atoms)
Use of Models • Sometimes we use MODELS to help us
understand what is happening at the
submicroscopic level
• These models are powerful tools to help
scientists predict the results of experiments.
• Ex: solar system
1. Substance changes in form or appearance
but does not change its chemical composition.
o Ex1: all phase changes (ex: ice melting)
o Ex2:cutting a piece of wood into small
pieces
2. Properties of that substance do not change
oEx: melting point
oEx: boiling point
oEx: chemical composition
3.Can be reversible* or irreversible
1. A substance changes into something new.
2. Occurs due to a chemical reaction.
3. Properties of the original substance change.
Ex:the density, melting point or freezing point of
original substance changes.
4. Common signs of a chemical change are often
observed (Ex: bubbles form, mass changes, heat
releases, etc).
5. Usually irreversible.
Classifying Matter by
Composition (what it’s made of)
•Substance
•Mixture
ALL MATTER IS EITHER A
OR
Don’t Copy: Leave a page in your notes for
this flow chart. We will complete it in class.
1. Can’t be further broken down by physical means.
2. Is pure matter
3. Has its own characteristic properties that are
different from those of any other substance.
4. Has fixed composition-every sample is the same
throughout
(Don’t copy: will go
on flow chart.)
Compounds
• Made of 2+ elements combined chemically.
• Can be decomposed into simpler substances by chemical changes.
• Elements always in a definite ratio
• Ex: H2O, NaCl
Elements
• Cannot be decomposed
into simpler substances
by chemical changes
• Ex: H, He, Li, Va
(Don’t copy: will go
on flow chart.)
1. 2 or more substances that are put together
but NOT chemically combined.
2. Components retain their characteristic
properties
3. May be separated into pure substances by
physical methods
4. Composition varies from sample to sample.
(Don’t copy: will go
on flow chart.)
Homogeneous-
• same composition
throughout
•ex: Kool-Aid
Heterogeneous-
•different composition
throughout
•large pieces-easily
separated by physical
means (ex: density,
filtration)
•ex: salad dressing
(Don’t copy: will go
on flow chart.)
•Solutions are homogeneous mixtures in
which there is a solvent& a solute.
•Examples: sugar water, 40% isopropyl
(rubbing) alcohol, brass
•Solvent: substance that dissolves
another substance. Ex: water
•Solute: substance that is being
dissolved. Ex: sugar
Separating Mixtures Filtration
• Process that separates a
solid from a liquid
• Uses a filter that has holes
that allow liquid to escape,
but solid particles are too
large
Decanting
• Pouring a liquid off the top
of a solid or another liquid.
Distillation
• separates a sol’n in which
the solvent has a low BP &
the solute has a high BP.
• Boil away the solvent, then
collect in a separate
container. see picture on p
47 (CHemIH) or
•STATES OF MATTER ARE:
•Solid
•Liquid
•Gas
•Plasma
•Others
KMT: Particles of matter are in
constant motion
Have definite shape
•Particles are in fixed positions
Have definite volume
•Particles touch so they can’t be
compressed
Particles move: they vibrate & rotate
Have no definite shape
Particles “flow” past one another.
Move more rapidly & freely than in
solids.
Have definite volume
Particles touch so they can’t be
compressed
Particles have “flow” (move around one
another freely)
•Have no definite shape
•Particles “flow” past one another.
•Have an indefinite volume
•Particles are far apart from one
another
•Particles move much more quickly
than in liquids.
•Ionized gas-made of ions and their freed
electrons
•Produced at very high temperatures
•Most common state of matter in the
universe-about 99% of known matter.
•Least common on Earth
•Found in plasma TVs, fluorescent lights
PRODUCTS IN WHICH
PLASMAS ARE USED:
(Copy a few of interest to
you.)
•Computer chips &integrated
circuits
•Computer hard drives
•Electronics
•Machine tools
•Medical implants&prosthetics
•Audio and video tapes
•Aircraft & auto engine parts
•Printing on plastic food
containers
•Energy-efficient window
coatings
•High-efficiency window
coatings
•Safe drinking water
•Voice and data
communications components
•Anti-scratch and anti-glare
coatings on eyeglasses and
other optics
Plasma-Based Water Treatment for
Water Sterilization (DO NOT COPY)
•intense UV emission disables the DNA of micro-
organisms in the water which then can’t replicate.
•no effect on taste or smell of the water and the
technique only takes about 12 seconds.
•effective against all water-born bacteria
and viruses.
•especially relevant to the needs of
developing countries b/c they can be made
simple to use and have low maintenance
and low cost.
•use about 20,000 times less energy than
boiling water!
Plasma-Based UV Water Treatment
Sytems, cont. (DO NOT COPY)
FYI: The slides that
follow are for your
interest
(Don’t need to copy any more from this
slide show.)
•Sir William Crookes, an English
physicist, identified a fourth state
of matter, now called plasma, in
1879
•The word "PLASMA" was first
applied to ionized gas by Dr.
Irving Langmuir, an American
chemist and physicist, in 1929.
(Above)
X-ray view of
Sun
from Yohkoh,
ISAS and NASA
Star formation in the
Eagle Nebula
Space Telescope Science
Institute, NASA
(below)
PLASMA
•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.
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.
•Waste processing
•Coatings and films
•Electronics
•Computer chips and
integrated circuits
•Advanced materials
(e.g., ceramics)
•High-efficiency
lighting
Plasma technologies
are important in
industries with annual
world markets
approaching $200
billion
High-temperature plasmas in arc furnaces
can convert, in principle, any combination
of materials to a vitrified or glassy
substance with separation of molten metal.
Substantial recycling is made possible with
such furnaces and the highly stable,
nonleachable, vitrified material can be used
in landfills with essentially no
environmental impact.
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