matter and energy
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MATTER AND ENERGY. - PowerPoint PPT PresentationTRANSCRIPT
MATTER AND MATTER AND ENERGYENERGY
MATTER
PART I
CLASSIFYING MATTER
Matter is anything having mass and volumeMatter is anything having mass and volume..
The Study of The Study of mattermatter and and how it changeshow it changes
Mass- the amount of matter in an objectMass- the amount of matter in an object
Mass is measured with a balance, unit is gramsMass is measured with a balance, unit is grams
• mass is related to weight but isn’t the same thing.mass is related to weight but isn’t the same thing.
• weight is dependent upon gravity.weight is dependent upon gravity.
• mass never changesmass never changes
Volume- anything that takes up space, unit L, cmVolume- anything that takes up space, unit L, cm33, , mLmL
is
4
IS AIR MATTER?
Does air have mass?Does air have volume?YES, to both, so air is matter
CompositionComposition- what matter is made of. Water is - what matter is made of. Water is made of hydrogen and oxygen (Hmade of hydrogen and oxygen (H22O), tea has O), tea has
caffeinecaffeine
PropertiesProperties-what matter is like. For example, -what matter is like. For example, water can dissolve many substances and water can dissolve many substances and caffeine is a stimulant.caffeine is a stimulant.
What caffeine is made of… What caffeine is like…
UEQ: In dealing with matter, how are composition, structure, properties and energy related?
LEQ: What are the differences between physical and chemical properties?
Extensive properties Intensive properties
• Depends on the amount of matter present
• Volume, mass, amount of energy in a substance
• Does not depend on amount of matter present
• Melting point, boiling point, density, ability to conduct electricity and transfer energy as heat
UEQ: In dealing with matter, how are composition, structure, properties and energy related?
LEQ: What are the differences between physical and chemical properties?
Physical changes Chemical changes
• Change that does not change the identity or chemical makeup of the substance
• Cutting, melting, drawing into wire, crushing, temperature and pressure changes
• Substance changes into new substance b/c chemical bonds have been broken or made
• Occurs on molecular level
• Noticed by temperature change, smell/odor, bubbles (gas), rust formation
• Reactants products
THE BASIC UNIT OF MATTER IS AN THE BASIC UNIT OF MATTER IS AN ATOMATOM
There are over 118 varieties of atoms
PERIODIC TABLE
http://www.webelements.com/scandium/
ELEMENTS contain only one type of atom.
Ex: hydrogen (H) is an element that contains only hydrogen atoms, carbon (C) contains only carbon atoms, oxygen (O) contains only oxygen atoms, etc.
Atoms of elements can combine together to form compounds.
COMPOUNDS are neutral groups of atoms held together by chemical bonds.
Ex: CO2, H2O, H2, O2
HOW DO WE CLASSIFY MATTER?
All matter is classified as either a pure substance or a mixture
Pure gold/Pure substance
24 karat
End of introductory material. Return to index
Alloy rims/ mixture of two metals
18 karat
CLASSIFYING MATTERPure substance-a type of matter where all
samples, no matter how big or small, have the same properties…they behave in exactly the same way.1. Elements2. Compounds
Elements contain one type of atom, thus they CANNOTCANNOT be broken down into simpler substances by chemical means.
Elements consist of either:single atoms, such as Carbon (C), or Sodium (Na)
groups of atoms of the same type (molecules), such
as H2, O2, Br2, etc.
ELEMENTSMONATOMIC ELEMENTS DIATOMIC ELEMENTS ALLOTROPES
Atomic nitrogen N Molecular nitrogen N2 Ozone O3
Atomic hydrogen H Molecular hydrogen H2 Graphite, buckyball
Atomic oxygen O Molecular oxygen O2
Carbon C
ALLOTROPE-different forms of an element in ALLOTROPE-different forms of an element in same physical statesame physical state
COMPOUNDS Compounds are substances made up of 2 or more different elements that are chemically combined. CO2, H2O, HCl, Na2SO4
COMPOUNDS CAN BE BROKEN DOWN INTO SIMPLER SUBSTANCES BY CHEMICAL MEANS ONLY.
COMPOUNDS HAVE DIFFERENT PROPERTIES THAN THE ELEMENTS THAT MAKE THEM UP.
Click on the links below to watch videos of compounds broken down into the substances that make them up.
Example-dehydration of sugar: C12H11O22 12C(s) + 11 H2O(g)-Sugar breaks down into carbon and water
Example-hydrolysis of water: 2H2O 2H2 + O2
• water breaks down into the hydrogen and oxygen gas which make it up.
http://www.all-science-fair-projects.com/science_fair_projects/38/819/5db524216341764c1438c1f760fddff8.html
http://earth2tech.com/2008/07/31/mit-solar-energy-storage-breakthrough/
ELEMENTS TO COMPOUND
Sodium, Na, is a soft, shiny metal that can be cut with a butter knife. When in contact with moisture it will “explode”.
Chlorine gas, Cl2, which is a green, poisonous gas once used as a chemical weapon in military operations.
COMBINED WITH…
Will Form…
Sodium metal and chlorine gas, under the right conditions, undergo a chemical change and combine to become…..
2 Na(s) + Cl2(g) 2 NaClThe final compound has properties different from the elements that formed it.
TABLE SALT!
1) We are studying CHEMISTRY, the study of ________and how it ________.
2) Matter is anything that has___ and takes up ___.
3) ___ are the basic building blocks of matter.
4) Matter can be classified as either a ___ or a ___.
5) Substances are either ___ or ___.
1. matter, changes 2. mass, space 3. atoms 4. pure substance, mixture 5. elements, compounds
Return to index
Answers:
MATTER
PURE SUBSTANCE
ELEMENT COMPOUND
Carbon (C) H2O
MIXTURE
?
NOW LETS DISCOVER MATTER AS MIXTURES
THUS FAR WE HAVE REVIEWED MATTER AS PURE SUBSTANCES.
MATTER AS MIXTURESMATTER AS MIXTURES Mixtures are combinations of 2 or more substances
where each substance retains its individual properties.
HOW ARE MIXTURES DIFFERENT FROM COMPOUNDS?
HOW ARE MIXTURES LIKE COMPOUNDS? THEY ARE MADE FROM TWO OR MORE SUBSTANCES
MIXTURES DO NOT FORM CHEMICAL BONDS.
There are two types of mixtures:
Classifying mixtures
2) HETEROGENEOUS1) HOMOGENEOUS
…a mixture that is the same throughout. A homogeneous mixture has a
composition and properties that are identical regardless of the sample
one phase
uniformly mixed
won’t settle out
small particles
Ways to identify a homogeneous mixture:
A SOLUTION is another name for a homogeneous mixture
is
… a mixture that is visibly differentthroughout. Heterogenous mixtures have a composition and properties that differ
in any given sample.
not uniformly mixed
more than one phase
will settle out
larger particles
is
Ways to identify a homogeneous mixture:
HETEROGENEOUS MIXTURESThere are special types of heterogeneous mixtures:• Suspensions-appear uniform when mixed but settle out.
– Chocolate Quik
– Muddy water
– Pulpy oj
– Oil & Vinegar dressing
• Colloids-appear uniform but they do not settle out. However, their particles are too large to be classified as a homogeneous solution.– Gelatin
– Milk
– Smoke
– Fog
– mayonnaise
TYNDALL EFFECTColloids are evenly mixed, but their particles are too
large to be considered homogeneous mixtures, which are also the same throughout.
Colloids show the Tyndall Effect. The Tyndall effect is the scattering of light as a beam passes through a colloid.
In each picture, the colloid on the left scatters the beam making it visible
MixturesSummary
Heterogeneous Mixture Homogeneous Mixture
Not evenly mixed Evenly mixed
Individual components retain their own properties
Properties of combined components are usually different than those of each component
Individual components can be easily seen
Individual components can not be easily seen
Can be easily separated Not as easily separated
Ex.: salt & pepper mix, rocks, cereal, bag of assorted candy
Ex. salt-water solution, tea, Cool-Aid drink
1. Tossed salad2. Salt water3. Kool-aid4. Muddy water5. OJ with pulp
Practice ProblemsPractice Problems
1. He 2. Ho 3. Ho 4. He 5. He 6. Ho 7. He 8. He 9. He 10. Ho
6. Tea7. Banana nut
bread8. Pizza9. Blood10. Brass
Determine whether each is a heterogeneous or homogeneous mixture:
Answers:
Return to index
• Pure Substances– Made of either elements or
compounds that are chemically bonded.
– Cannot be separated by physical means.
– When combined they take on new properties different from the original elements.
– Examples:• Glucose: C6H12O6
• Table Salt: NaCl• Oxygen Gas: O2
• Carbon Dioxide CO2
• Mixtures:– Two or more substances mixed
together but not chemically combined.
• Tea = Crushed Leaf + H2O• Rocks = minerals + sediments +
organic matter• Sugar Water = Sugar + H2O
– Each component retains its own identity; it does not change into something else.
– Can be separated by physical means
– Examples:• Sweet tea• Trail mix• Air (O2, N2, CO2, Ar)
Now, lets put it all together and determine how to tell substances (compounds and elements)
from mixtures.
Elements, Compounds, and Mixtures
Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 68
hydrogenatoms
oxygen atomshydrogenatoms
Two of the descriptions to the right apply to each bottle below. Determine the appropriate descriptions..
a. Two types of atoms evenly mixed
b. Two types of atoms chemically combined
c. One type of atom
d. Two types of atoms mixed
e. An element
f. A solution
g. A compound
h. A mixture2_______1_______ 3_______ 4_______d & h b & g c & e a & f
Return to Index
Classifying Matter
Matter
Pure Substances Mixtures
Elements Compounds
Homogeneous Heterogeneous
He, O H2O, NaCl
Tea, kool-aid Rocky Road ice cream, muddy water
Review: How matter is classified
Classify the following substances as:Pure substance, heterogeneous mixture, or homogeneous mixture
Gatorade Homogenous mixture
Fruit Loops Heterogeneous mixture
Pure substanceGasoline
Dirt Heterogeneous mixture
Sugar Crystals Pure Substance
Air Homogeneous mixture
Granite Heterogeneous mixture
Return to index
More review