2. Chemistry
• A physical science
that involves the study
of the properties,
composition,&
structure of matter and
the changes it
undergoes.
3. What is a chemical?
• Any substance
that has a definite
composition or is
used or produced
in a chemical
process.
• Sugar is an example of a
chemical
4. • Everything that has
mass and volume is
called matter
• Can be simple as in
elements on the
Periodic Table
• or complex molecules
as atoms combine
Elements in the same vertical
row will behave similar in
chemical reactions
5. Three Major Classes of Elements
• Metals- located on the left of the Periodic Table- most
of the elements
• Non-Metals- located on the right of the Periodic Table
• Metalloids- on the zigzag line between Metals and
Nonmetals- have properties that are skewed- ie…
Silicon is conductive
• You will have to memorize the symbol and element
name for approximately 40 common elements
6. Properties of Metals
Metals are good
conductors of heat and
electricity
Metals are malleable
(can be
shaped)
Metals are ductile (can
be drawn into wires)
Metals have high tensile
strength
Metals have luster
7. Properties of Nonmetals
Carbon, the graphite in “pencil lead” is a great
example of a nonmetallic element.
Nonmetals are poor conductors of heat and
Electricity
Nonmetals tend to be brittle
Many nonmetals are gases at room
temperature
8. Atoms Unite To Form
Compounds
• Chemical Formula
C16H10 N2O2.
indicates number
and type of atoms
within the molecule
The formula to the
left is the molecule What type of atoms and how
for indigo: many are there in one molecule?
9. What is not matter?
• Light
• Electricity
• Sound
10. • Fixed composition
• Cannot be separated into simpler substances by
physical methods (physical changes)
• Can only be changed in identity and properties by
chemical methods
• Properties do not vary- Unique Density, Constant
Boiling and Melting Points
11. Elements Compounds
• Cannot be • Chemically joined
decomposed into elements- Can be
simpler decomposed into
simpler substances by
substances by chemical changes,
chemical changes always in a definite
ratio
12. • Variable composition
• Components retain their characteristic properties
• May be separated into pure substances by physical
methods sifting, evaporation, magnetism, etc…
• Mixtures of different compositions may have
widely different properties
• Do NOT have definite boiling/melting points
13. Homogenous mixtures look the same
throughout but can be separated by
physical means
Examples: salt water, soda
14. • Have the same composition throughout
• Components are indistinguishable
• Can exist between all phases of matter:
air (gases) brass (alloy- blend of
multiple metals -solids)
soda (gas, solid, liquid)
15. Adding Liquids Together
• Miscible- will mix-
water and alcohol
• Immiscible- wont mix
water and oil
16. Solutions are homogenous mixtures that
do not scatter light. These mixtures are
created when something is completely
dissolved in pure water. Therefore, they
are easily separated by distillation or
evaporation. Appear in one phase of
matter
Examples: sugar water, salt water
17. Parts of a solution
• Solvent- part that does
the dissolving- water
is our universal
solvent
• Solute- part that was
dissolved (salt)
18. How do we increase solubility of
a solid into a liquid
• Heat it- more
collisions between
solute and solvent
• Mix- Fresh solvent to
solute
• Crush- more surface
area- more contact
19. Increase solubility of a gas in a liquid
• Henrys Law- solubility of
the gasis directly
proportional to the
pressure above the liquid-
• Effervescence- rapid
escape of gas from liquid
• Decrease temperature-
slows down diffusion
20. Heterogeneous mixtures are composed of
large pieces that are easily separated by
physical means (ie. density, polarity,
metallic properties, size).
Pond Water, Vegetable Soup- Suspensions
Visible particles
Starch Water: invisible to the eye :colloid
21. Colloids are Tricky
• Some heterogeneous
mixtures appear as
solutions to the eye:
• Blood, Milk, starch
water
• Need a test: Tyndall
Effect a light will scatter
the suspended particles
22. MATTER
yes Can it be physically
no
separated?
MIXTURE PURE SUBSTANCE
yes Is the composition no yes Can it be chemically no
uniform? decomposed?
Homogeneous Heterogeneous
Mixture Mixture Compound Element
(solution)
Colloids Suspensions
Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem
23.
24. Physical Properties – Observable traits
of a material that may be measured
without altering the substance
Examples: Mass, Color, Melting Point,
Boiling Point, Density
25. We can use physical properties to
separate mixtures:
Please determine a method to separate the following and
determine the type of matter:
Oil and Water
Iron and Sand
Sand and Salt
Sulfur and Sugar
26. What are the
physical properties
of the substance to
the right?
What do you think the material is that made this
bracelet?
How could you be sure?
Density- the amount of material in a given
volume- unique to the material
28. • 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
29. Energy comes in two forms :
Kinetic Energy: Movement
Potential Energy: Stored
30. All matter, regardless of state, undergoes
physical and chemical changes. These
changes can be microscopic or
macroscopic.
31. A physical change occurs when the
substance changes state but does not change
its chemical composition. It is not
permanent and is reversible! Example
Phase Changes!
32. Physical Change
For example: Ice melting to
water. 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.)
33. • Melting point • Density
• Boiling point • Electrical conductivity
• Vapor pressure • Solubility
• Color • Adsorption to a
• State of matter surface
• Specific Heat • Hardness
34.
35. Names of Water Phase Changes
Endothermic Requires Exothermic Gives
Energy to go forward energy off
• Melting: Solid Liq • Condensation
• Boiling (forced) Gas Liq
Liquid Gas • Freezing:
• Evaporation ( spon) Liq Solid
Liquid Gas • Deposition:
• Sublimation Gas Solid
Solid Gas
37. Indications of A Chemical Reaction
• Bubbles- gas given off
• Change in energy- becomes
warm- exothermic
becomes cool- endothermic
light is given off
• A precipitate (solid) forms
• Sometimes a change in
color-
38. All Chemical Changes can be
written as a reaction
• A + B AB
• A, B are the starting
materials- reactants
• AB is the result-
product
39. • 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
40. • Physical and chemical properties may be
intensive or extensive.
41. • Intensive properties such as density, color, and
boiling point do not depend on the size of the
sample of matter and can be used to identify
substances.
•
43. • Physical properties are those that we can
determine without changing the identity of
the substance we are studying.
44. • 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.
45. Specific Heat
• Physical Property that is unique
to the material
• Amount of energy required to
heat 1 gram of a substance by 1
degree Celsius
• -Why do you choose to sit on the
wooden bleachers on a cold fall day
for a football game instead of the
metal bleachers?
46. • 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.
47. • 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.
• In other words, we have to define chemical
properties of a substance by the chemical changes
it undergoes.
48.
49. & The Kinetic Molecular Theory
•All matter is made of atom and molecules that
act as tiny particles
•These particles are always in motion (yes even in solids)
•The higher the temperature the faster the
particles move-
•Kinetic energy is directly proportional to Kelvin
Temperature ( bigger particles move slower)
52. •Have a definite shape
•Have a definite volume
Kinetic Molecular Theory
Molecules are held close together
and there is very little movement
between them. Vibrational
53. •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”.) Has 2 dimensional
motion- can slide past each other
54. •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.
55. At 100°C, water
becomes water
Between 0°C and 100 vapor, a gas.
°C, water is a liquid. Molecules can
In the liquid state, move randomly
water molecules are over large
close together, but distances.
can move about
freely.
Below 0°C, water
solidifies to become
ice. In the solid state,
water molecules are
held together in a
rigid structure.
56. 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 formation, Hf. Heat of vaporization, Hv
57. Plasma is by far the most common form
of matter in the universe (not here on
Earth). 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. Fluorescent Light Bulbs…
58. Star formation in the
Eagle Nebula
Space Telescope Science Institute
, NASA
(below) (Above)
X-ray view of
Sun
from Yohkoh,
ISAS and NASA
60. Laser plasma interaction during inertial
confinement fusion test at the
University of Rochester.
61. 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.
63. 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
Hinweis der Redaktion
Basic definition of matter.
Basic characteristics of pure substance:
The two categories of pure chemical substances.
Basic identification of a mixture.
Brainstorm more examples of homogenous mixtures.
Definition of Conservation of matter.
Definition of physical changes.
Physical changes are characterized by the following:
Definition of chemical change.
Chemical Changes are characterized by the following: