Alloys

1
Alloys

• Solid Solution (A solution is a homogeneous
  mixture)
• Stainless steel, bronze, brass, sterling silver,
  14-karat gold, solder
• Usually contains different metals and sometimes
  nonmetallic substances

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Properties of Matter
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Properties of Matter

• Can be QUALITATIVE
• No measurement necessary (Quality)
• The solid is hard.
• Can be QUANTITATIVE
• Uses measurement (Quantity)
• Iron has a density of 7.86 g/ml.

4
The temperature is 98o F

• A. Qualitative
• B. Quantitative

5
Sucrose is composed of C, H, O

• A. Qualitative
• B. Quantitative

6
The sky is blue.

• A. Qualitative
• B. Quantitative

7
I weight 99 pounds.

• A. Qualitative
• B. Quantitative

8
Write---

• Qualitative and Quantitative Observations of a
  Candle
• Write 10 qualitative observations and 10
  quantitative observations about a burning candle.

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Physical Properties
10
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• What are some properties that might be used to
  identify matter?

11
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• Color
• Solid, liquid, gas
• Does it burn?
• Does it dissolve in water?
• What happens when you mix something with it?

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Physical Properties

• Characteristics that matter exhibits without any
  change in its identity

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Physical Properties

• Solubility (dissolves)
• Physical State (solid, liquid, gas)
• Temperature at which it changes from one state to
  another (Melting Point, Boiling point)
• Color
• Density (mass/volume)
• Electrical Conductivity
• Odor
• Viscosity (how easily it flows)

14

• Name a physical property!!

15
Physical Changes
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Physical Changes

• Change in matter that does not involve a change
  in the identity of individual substances
• Separate a Mixture using Physical Changes
• The same elements/compounds are there before and
  after

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Physical Changes

• No dramatic changes!!

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Examples of Physical Changes

• Boiling
• Freezing
• Melting
• Evaporating
• Dissolving

19

• How can you separate sugar and sand using
  physical changes?

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Chemical Properties
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Chemical Properties

• There must be a change in the composition of the
  substance-something new is formed
• The ability of a substance to react with other
  substances or decompose (break down) into other
  substances

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Chemical properties

• Rusts
• Reacts with another substance
• No reaction
• Broken down into simpler substances
• Prevents oxidation
• Breaks down in light
• Formation of gases
• Evolution of light and heat
• Absorption of energy

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Chemical changes
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Chemical Change (Chemical Reaction)

• The change of one or more substances into other
  substances
• Involves some sort of energy change

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Chemical Changes

• VERY DRAMATIC CHANGES!!!

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Hints that a chemical change has occurred.

• Heat is released or it becomes colder
• Light is produced
• Color changes
• Gas is produced
• Produces a solid (precipitate)

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(No Transcript)
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Type of Energy changes

• Exothermic
• Give off heat
• Dynamite-explosion of nitroglycerin
• Endothermic
• Absorb/Needs heat
• Photosynthesis need light energy from sun

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Burning a log

• A. Exothermic
• B. Endothermic

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Demonstration (p42)

• Physical or Chemical Change
• Add iron chloride to water
• Add potassium thiocyanate to same water
• Add magnesium ribbon to hydrochloric acid

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Physical or Chemical property??
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Baking Soda is a white powder

• A. Physical property
• B. Chemical property

33
Acid is corrosive.

• A. Physical property
• B. Chemical property

34
Fluorine is a highly reactive element.

• A. Physical property
• B. Chemical property

35
Aluminum bends easily

• A. Physical property
• B. Chemical property

36
Copper conducts electricity.

• A. Physical property
• B. Chemical property

37
Sodium reacts with water.

• A. Physical property
• B. Chemical property

38
Gasoline is flammable.

• A. Physical property
• B. Chemical property

39
Iron does not resist corrosion.

• A. Physical property
• B. Chemical property

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It boils at 88 degrees.

• A. Physical property
• B. Chemical property

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Physical or Chemical Change?
42
A pan of water boils on the stove.

• A. Physical change
• B. Chemical change

43
A match lights when struck.

• A. Physical change
• B. Chemical change

44
Ice cream melts

• Physical Change
• B. Chemical Change

45
Sodium reacts with water

• Physical Change
• Chemical Change

46
Baking soda bubbles and gives off carbon dioxide
when it is moistened

• A. Physical change
• B. Chemical change

47
Change from solid to liquid from gas to liquid

• Physical Change
• Chemical Change

48
Squeeze a HOT HANDS and the pad warms up.

• A. Physical change
• B. Chemical change

49
A lump of gold is pounded into a large, thin
sheet.

• A. Physical change
• B. Chemical change

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Air is squeezed by a pump and forced into a tire.

• A. Physical change
• B. Chemical change

51
Salt is dissolved in water.

• A. Physical change
• B. Chemical change

52
An explosion occurs.

• A. Physical change
• B. Chemical change

53
Charging a car battery

• A. Physical change
• B. Chemical change

54
Isopropyl alcohol evaporates.

• A. Physical change
• B. Chemical change

55
A firefly lights up.

• A. Physical change
• B. Chemical change

56
Hammer hot iron into a thin sheet.

• A. Physical change
• B. Chemical change

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Digestion-Physical or Chemical?

• Physical
• Chewing breaks food into smaller pieces

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Digestion-Physical or Chemical

• Chemical
• Large molecules (like starch and proteins) are
  changed into simple sugars and amino acids

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Oxidation-Physical or Chemical?

• Chemical
• Iron and oxygen form a new substance--rust

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The Rock Cycle-Physical or Chemical?
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Rock Cycle

• Sediments are deposited-Physical
• Sediments (under pressure) turn into sedimentary
  rocks-Physical
• Sedimentary rocks (under heat and pressure) turn
  into metamorphic rocks- Chemical
• Metamorphic rocks melt into magma-Physical
  Chemical
• Magma cools and forms new rock with new
  minerals-Physical Chemical

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Law of conservation of Mass

• In a chemical change, matter is neither created
  nor destroyed
• Atoms do not disappear