Chapter 1 Chemistry: the Science of Matter

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Section 1.1
The Puzzle of Matter
Objectives
 Classify matter according to its composition
 Distinguish among elements, compounds,
homogeneous mixtures and heterogeneous
mixtures
 Relate the properties of matter to structure
Review of terms
 Accuracy – the accuracy of a measurement is how
close a result comes to the true value.
 Precision - refers to the closeness of two or more
measurements to each other. Using the example above,
if you weigh a given substance five times, and get 3.2
kg each time, then your measurement is very precise.
Chemistry
Investigates and explains the structure, composition,
and behavior of matter
(how it is made and organized)
It is the WHAT, HOW, and WHY of stuff
Composition and Behavior
But what is matter?
Matter is anything that takes up space and has mass.
…and what is mass?
Mass is the measure of the amount of matter that an
object contains.
Question: What is the SI unit for mass?
Properties of Matter
Properties describe the characteristics and behavior of
matter
How do I determine the properties of matter?
 Examine it
 Manipulate it (burn it, dissolve it, mix it)
 Take measurements
The Macroscopic View of Matter
Macro – prefix – what does it mean?
If you can touch, feel, smell, taste or see it, you are
viewing matter from a macroscopic perspective
The Submicroscopic View of
Matter
Submicro – prefix – what do you think it means?
Submicroscopic
 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
Models in Chemistry
Give an example of how a model is used?
A scientific model is a thinking device that helps you:
1) Understand and explain the observed behavior of
matter
2) Predict behavior that has yet to be observed
Must be supported by experiments
Classifying Matter
QUALITATIVE: Observation without measurement
Ex: Strong girl, blue dress, Tall man
QUANITATIVE: Observation with measurements
Ex: 100 lbs., 5 dresses, Man is 6 ft. tall
Pure substance or a mixture?
 PURE SUBSTANCE: Matter that has the same fixed
composition and properties (element or compound)
 MIXTURE: Combination of two or more substances in
which the basic identity if each substance is not
changed - composition is variable
Pure Substances
ELEMENTS: Substances that cannot be broken down
into simpler substances (simplest form of matter)
 There are ~117 elements, 92 occur naturally on Earth
 https://www.youtube.com/watch?v=v1TfPDlA1xE
COMPOUNDS: Chemical combinations of two or more
elements, joined together in fixed proportions with a
unique set of properties
Mixtures
Can be separated through physical processes – name a
physical process
- i.e. filtration
 PHYSICAL CHANGE: A change in matter that does not
involve a change in the identity of the individual
substances
Examples: freezing, melting, evaporating, cutting
 PHYSICAL PROPERTIES: characteristics matter exhibits
without any change in its identity
Examples: solubility, melting point, density
Mixtures
2 Types of mixtures:
Heterogeneous: a mixture with different compositions
Has clear and distinct regions, called phases.
Homogeneous: a mixture that is the same throughout
(constant composition) also called a SOLUTION
Solutions can have water, gases, solids
Mixtures (cont)
ALLOYS: solid solutions that contain metals and
sometimes nonmetals. No water!
 Ex: Stainless Steel (Fe, Cr, Ni), Brass (Cu and Zn)
Mixtures (Cont)
Aqueous solutions: Contain water.
Solute:
The substance that is dissolved.
Solvent:
The substance that dissolves the solute.
Example:
In Kool-Aid what is the solute and what is the solvent?
Graphic Organizer
 Draw on board
Graphic Organizer
Organizing elements
 Periodic table organizes elements and provides
chemical information.
 Periodic tables in textbook on p. 90-91, back cover.
 Chemical symbols are universal shorthand- 1 or 2 letter
symbols.
Ex: O (oxygen) -corresponds to English name
Cu (copper)- corresponds to Latin name (cuprum)
Compounds
More than 10 million compounds
(Common compounds on p. 30)
 FORMULA: Combination of chemical symbols that
shows which elements and how many make up a
compound
Ex: H2O (water), C12H22O11 (Sucrose)
Group Activity:
Pure vs. Compound
Homogeneous vs. Heterogeneous
Grouping/Sorting Matter Activity
 Sugar and Sand
 Salt and Water
 Sulfur (S)
 Stainless Steel
 Milk
 Spaghetti and meatballs
Activity
 Organize the matter from the list below into 2
categories~ PURE and MIXTURE
Granola
Sugar
Sterling Silver
Air
Diamonds
Dihydrogen Monoxide
Uranium
Ink
Natural Gas
Bronze
Activity
 Now…
 Separate your PURE matter into elements and
compounds.
Activity
 NOW…
 Separate your MIXED matter into homogeneous and
heterogeneous.
Stop!
 Highlight vocabulary or unknown words.
 Circle any examples you had written down
 Write 3 questions. Turn to the person next to you and
share your question. Write down their question
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