Post on 05-Jan-2016
Molecules, Mixtures, and Reactions
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Atoms don’t always exist alone.
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Atoms don’t always exist alone.
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I’m stable! Me too!
Sometimes atoms become more “stable” when combined with other atoms. Together, they are called a Molecule.
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We Are Stable
Together!
Sometimes atoms become more “stable” when combined with other atoms. Together, they are called a Molecule.
Molecules
• Molecules: When two or more atoms combine.
• On the left is an example of Sodium (Na) joining with Clorine (Cl) to make NaCl, table salt.
Image Courtesy of http://lc.brooklyn.cuny.edu/smarttutor/core3_21/images/nature/9.a.Ionicbond-nacl.gif
Two Types of MoleculesMolecules
Elements Compounds
Elements are molecules that consist of only one type of atom.
Compounds are molecules that consist of two or more different types of atom.
Examples:1) O2
2) O3
3) H2
Examples:1) H2O2) CO2
3) C6H12O6
Elements
O2
O
OH2
H
H
O3
O
O
O
Compounds
H2O
Cl
Na
NaCl
H
H
CO2
C
O
O
O
Mixtures
Two Types of MixturesMixtures
Homogeneous Heterogeneous
Homogeneous means that the mixture can be physically separated back to their original forms, if needed.
Heterogeneous means that one part has dissolved into another part to make something that can only be separated using chemistry.
Examples:1) Box of crayons2) Jar of different colored
marbles3) Bag of Halloween Trick or
Treat candy.
Examples:1) Kool-aid2) Saltwater3) Lemonade Mix
Heterogeneous Mixture
Image Courtesy of http://flatographics.com/images/how_11.jpg
Heterogeneous Mixture
Image Courtesy ofhttp://imagecache2.allposters.com/images/pic/NGSPOD05/112503~Close-View-of-Colorful-Glass-Marbles-in-a-Jar-Posters.jpg
Heterogeneous Mixture
Image Courtesy http://farm1.static.flickr.com/65/188741790_21e785c8ce.jpg
Homogeneous Mixture (Solution)
Image Courtesyhttp://www.stjamesfestival.org/07Koolaid.gif
Homogeneous Mixture (Solution)
Image Courtesy of Mr. Lin
Homogeneous Mixture (Solution)
Image Courtesy of http://www.dkimages.com/discover/previews/944/50508273.JPG
Solute: The part that will be dissolved
Solvent: The part that will dissolve the solute.
Physical Versus Chemical Reaction
Physical Reaction
• Physical Reaction: Occurs when something happens, but it remains the same material.
• Examples: – Ripping Paper– Molding Clay– Cutting WoodImage Courtesy of
http://www.martialartsinsurance.com/NR/rdonlyres/0D7F63AB-A236-44F7-97C9-208E40917DF5/0/BoardBreak.jpg
Chemical Reaction• Chemical Reaction:
Occurs when something happens, and the end result is a totally different material than how it started.
• Examples: – Burning Paper– Food Digesting
Image Courtesy of http://tiee.ecoed.net/vol/v3/issues/frontier_sets/yellowstone/img/forest_fire%5BHR%5D.jpg
Signs of a Chemical Reaction: Change in Color
Image Courtesy of http://static.panoramio.com/photos/original/286439.jpg
Image Courtesy of http://content.answers.com/main/content/wp/en/thumb/7/75/250px-Late_model_Ford_Model_T.jpg
Signs of a Chemical Reaction: Change in Smell or Taste
Image Courtesy of http://images.jupiterimages.com/common/detail/71/14/23031471.jpg
Image Courtesy of http://www.roadfood.com/photos/4340.jpg
Chemical Reactions
(Show “Traits of Chemical Reactions” Video Segment)