Ch. 15 Notes.notebook
January 23, 2017
Friday, January 20th, 2017
Composition of Matter
1) Check in cell phones
A. Substance­ either an element or a compound
2) Answer the QOTD:
"All matter is composed of __________."
3) take out vocab for ch. 15
1. When all the atoms in a substance are alike, the substance is an element.
­cant be broken down
­ examples: Carbon, Hydrogen, Nitrogen
Jan 19­10:04 AM
2. A compound is a substance with two or more elements combined in a fixed proportion
­ materials made from atoms combined
­can't be broken down by physical processes
­ example: sugar, Carbon dioxide (CO2)
Jan 19­10:06 AM
B. Two or more substances that can be easily separated by physical means form a mixture.
1. Heterogeneous mixture­ mixture of different and easily distinguishable materials. » Different materials easy to distinguish
» Pizza, concrete, salad
Jan 19­10:48 AM
2. Homogeneous mixture­ contains two or more gaseous, liquid, or solid substances blended evenly; also called a solution.
>
A homogeneous mixture keeps a uniform appearance when two or more substances are mixed.
Jan 19­10:54 AM
3. Colloids­ heterogeneous mixture with larger particles that do not settle
• Particles are large enough to scatter light (Tyndall effect)
• Examples are milk, fog, smoke, and gelatin
» vinegar, tea, hot coffee
» plasma
» water (contains dissolved gases and minerals.) Jan 19­11:37 AM
Jan 19­11:37 AM
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Ch. 15 Notes.notebook
January 23, 2017
4. A heterogeneous mixture containing a liquid in which visible particles settle is called a suspension.
• particles in these settle upon standing
• can be separated using filter paper
• particles in these are large enough to scatter light.
• Examples; muddy water, open can of pop, orange juice
Jan 19­11:46 AM
Jan 20­10:22 AM
Word Sort Key
Solution
Element
Compound
One kind of atom
two or more kinds of atoms One substance dissolved in another
sugar
homogeneous
water
alloys
salt
air
*pure substance
Gasoline
Periodic Table
Aluminum
Carbon
Oxygen
*pure substance
Mixture
easily separated by physical means
heterogeneous
pizza
trail mix
concrete
Kool‐Aid
potting soil
soda
suspension
lemonade
fog
milk
Jan 20­10:18 AM
Monday, January 23rd, 2017
Jan 20­8:58 AM
SR #1 p. 456
1.
1) Write in planner for the week
2) No QOTD this week
3) Take out Note­taking wksh & SR p. 456
2.
3.
4.
Jan 20­3:03 PM
Both compounds and homogeneous mixtures are made of more than one substance/ element and are homogeneous. However, compounds must be made from elements in an exact ratio and involve chemical bonds between the elements in them.
A substance must either be an element or a compound. Mixtures can be made from combinations of compounds or elements.
Colloids do not settle out (ex. milk); suspensions eventually do settle out(ex. orange juice). Particles in colloids are smaller than particles in suspensions.
since the particles in suspensions settle out.
Jan 23­8:15 AM
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Ch. 15 Notes.notebook
Sec 2­ Properties of Matter
A. Physical properties­ characteristics that can be observed without changing matter composition.
> Appearance and/or behavior
> e.g.­ color, odor, shape, mass, volume, density, viscosity, malleability, texture, conductivity, state, bp, fp..
Jan 19­11:50 AM
B. Physical change­ alters the substance's size, shape, or state of matter.
1. Substance does not change identity when it undergoes a physical change.
– e.g.­ breaking, bending, tearing, grinding, melting, freezing, vaporization (liquid­­> gas)
Jan 19­11:57 AM
Chromatography­ technique for separating complex mixtures into their individual compounds based on differences between them.
January 23, 2017
1. Appearance­ physical description of a substance
2. Behavior­ how a substance acts (magnetic, viscosity, ductility)
3. Physical properties such as size can be used to separate mixtures.
Jan 23­8:25 AM
2. Distillation­ a process for separating a mixture by evaporating a liquid and condensing its vapor. Jan 19­12:00 PM
Chromatography: How it works...
­solubility/ polarity
­size
­charge
Jan 23­8:39 AM
Jan 19­12:21 PM
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Ch. 15 Notes.notebook
January 23, 2017
C. Chemical properties­ characteristics of a substance that are observed by changing matter composition.
D. When one or more substance changing into a new substance, a chemical change has occurred.
e.g.­ oxidation (reacts with oxygen), flammability, reactivity with light or other substances, electrolysis
1.
Jan 19­12:07 PM
2. Other chemical changes occur very slowly, such as the formation of rust.
3. Chemical changes can be used to separate substances such as metals from their ores. Jan 19­12:12 PM
F. Law of conservation of mass­ mass of all substances present before a chemical change equals the mass of all substances after the change. Jan 19­12:15 PM
e.g.­indicated by change in temperature, smell, color, release gas/ fizz, odor, sometimes produce sound/ light.
Jan 23­8:42 AM
E. Weathering of Earth's surface involves both physical and chemical changes.
1. erosion­ big rocks split into smaller ones; streams carry rock particles from one location to another.
2. corrosion­ chemical changes can occur in rocks when calcium carbonate in limestone changes to calcium hydrogen carbonate due to acid rain. Jan 19­12:13 PM
Practice Problems p. 463
Jan 25­8:25 AM
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Ch. 15 Notes.notebook
SR Probs. p. 465
January 23, 2017
Tuesday, January 26th
1) What physical properties could be used to describe/ identify these minerals?
Jan 25­8:23 AM
Jan 26­8:42 AM
Enrich wksh
1) Check in cell phones
Matter
e
Wednesday, January 27th
n b
ca
n be
ca
Mixtures
Substances
2) Answer the QOTD:
"In your own words, explain the difference between a physical and a chemical change."
Elements
compounds
Homogeneous
Solutions
3) take out Enrich wksh and a pen Jan 27­8:57 AM
Colloids
Heterogeneous
Suspensions
Jan 30­1:19 PM
Thursday, January 28th
1) Check in cell phones
2) Answer the QOTD:
"When a firecracker explodes what happens to mass? Is this an example of a physical or a chemical change? 3) Take out physical and chemical change lab
Jan 27­9:28 AM
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