Download Section 1 - School District 27J

Section 1.1
The Puzzle of Matter
What is
chemistry?
What are
properties of
matter?
A science that investigates and explains
Matter’s structure
 What it is made of (composition)
 How it is organized
Matter’s properties
 The characteristics and behavior
 The changes that it undergoes
What is matter and
what is it made of?
Matter is anything that takes up space and has
mass.
What is mass?
 Review - Hint: Inertia
 In chemistry, the unit of measure for mass is
the kilogram (metric)
Demo 1:
Water/Alcohol
Floating Ice Cubes
Demo 2: Lighting
Water on Fire
Demo 3: Chalk vs.
Magnetic Stir Bar
Examples:
 What do these forms of matter have in
common?
 What makes these different?
 What are these examples of matter made of?
Models in Chemistry
What is a scientific
model?
A scientific model is a thinking device that helps
you understand and explain macroscopic
observations.
What are some
analogies that will
help us think about
models?
What do the football team, school choir, chemistry
class, and U.S. Congress have in common?
Compare this with Figure 1.7 Aspirin and Sucrose
Demo: Sucrose
and Sulfuric Acid
Sucrose: C12H22O11
Sulfuric Acid: H2SO4
What is an
element?
The simplest form of matter. They are pure! They
are found on the Periodic Table
What is a
compound?
A chemical combination of two or more elements
joined together in a fixed proportion. (Let’s look
at some models.)
What is a formula?
A combination of the chemical symbols that show
what elements make up a compound.
What is a
macroscopic view
of matter?
The Macroscopic View of Matter
 If you can touch, feel, smell, taste or see it,
you are viewing matter from a macroscopic
perspective.
What is a
submicroscopic
view of matter?
The Submicroscopic View of Matter
 So small that you can’t see it with a
powerful microscope!
 You are “viewing” the world of atoms
 No one has ever seen a single atom, but
there is indirect evidence that supports its
existence
What is qualitative
and quantitative
classification?
Classification by Composition
 Qualitative: color, texture, state of matter
 Quantitative: mass, volume, density
Demo: Make a
Prediction –
Separation of
Mixed Matter ~
Ink
Chromatography
What is a pure
substance?
What is a mixture?
What are
solutions?
What are alloys?
What are aqueous
solutions, solutes,
and solvents?
Group Activity:
Pure vs.
Compound
Homogeneous vs.
Heterogeneous
Pure or Mixture?
 Pure Substance: every bit of matter
examined is made up of the same “stuff”, all
of which have the same fixed composition
and properties.
 Heterogeneous Mixture: a mixture with
different compositions; has clear and distinct
regions, called phases.
 Homogeneous Mixture: a mixture that is
uniform, or the same, throughout. Also
called solutions.
 IN EACH EXAMPLE, the components of
the mixture RETAIN their unique properties
Solutions are homogeneous mixtures.
Solutions do not always contain water!
 Alloys: Solid solutions that contain different
metals and sometimes nonmetals. No water!
 Aqueous solutions: Contain water.
o Solute: The substance that is
dissolved.
o Solvent: The substance that dissolves
the solute.
o Example: Kool-Aid
Grouping/Sorting Matter Activity
 Sugar and Sand
 Salt and Water
 Iron (Fe) and Sulfur (S)
 Brass and Stainless Steel
 Carbon and Aluminum
 Calcium Carbonate and Chalk
Section 1.2
Properties and Changes of Matter
How can you
identify matter by
its physical
properties?
Physical properties do not involve changes in
composition.
 Freeze or Melt: Substances freeze and/or
melt at the same temperature. Units of
measurement are F, C, & K Example:
Water state change @ 0C
 Boiling or Condensing: Substances boil
and/or condense at the same temp. Example:
Water state change @ 100C
 The color of a substance can also help with
classification of matter.
What is density?
Density is the amount of matter (mass) per unit of
volume.
 Units of measurement are usually grams per
milliliter (g/ml), but can also be expressed as
grams per cubic centimeter (g/cm3) 1 ml = 1
cm3
 Example: Determining density of a solid
sample using water displacement.
 Example: What is the density of a metal if
35 g takes up a volume of 15 cm3?
Physical states of matter include solid, liquid, gas,
and plasma
 Examples of different states of matter:
I2 (s) C2H5OH (l) CO2 (g)
 Are these molecules themselves solid, liquid
and gas?
NO! Physical state is determined by how the
molecules are arranged. Depending on
temperature, iodine can be a vapor; ethanol and
carbon dioxide can be solids!
A change in state is nothing more than a physical
change!
What is a volatile
substance?
Demo: Potpourri
Balloon
(Air Freshener)
How can you
identify matter by
its chemical
properties?
Demo:
Mini-Lab 1
50ml + 50ml
Now Separate!
Distillation or
Light it on Fire!
What is the law of
conservation of
mass and how
does this help us
understand
chemical rxn?
Demo 1.4
Conserving Mass
VOLATILE means that a substance can change
easily to a gas at room temperature
 Examples: gasoline, alcohol, and
naphthalene, vanilla
Chemical properties and changes:
 Can only be observed by change in
composition.
 Chemical change () =
Chemical reaction (rxn)
 Other evidence of chemical change: Gases
form, color changes, precipitation forms
(insoluble product)
 Energy is either given off or taken in
o Exothermic: energy out
Ex. digestion, match burning
o Endothermic: energy in
Ex. photosynthesis, baking
Law of Conservation of Mass: In a chemical
change, matter is neither created no destroyed –
atoms don’t just disappear!
EINSTEIN: Mass and energy are the same;
E = mc2