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Ch 2 Classifying Matter
Draw the following chart on your paper make it big enough to fill the page & large enough to write in boxes
Matter
Pure SubstanceMatter that always
has same composition
MixturesComposition is not fixed
Pure Substance• Matter that
always has exactly same composition
ex:
• salt
• sugar
• gold
Pure Substance
ElementCannot be broken
down into simpler substances
CompoundMade from 2 or more elements
Element• Atom—the
smallest particle of an element
• Ex: Carbon (C), Oxygen (O), Neon (Ne), Carbon (C), Platinum (Pt), Mercury (Hg)
Compound
• Always joined in a fixed proportion
• Ex: –Water (H2O)
–Salt (NaCl)
–Steam
Mixtures
Heterogeneousdifferent parts
are noticeably different
Homogeneoussubstances are
uniformly distributed
Mixture-Homogeneous
• Homogeneous mixtures contain substances that are uniformly spread out
• aka: Solution
• Ex: Vinegar, Syrup
Homogeneous
Aka: SolutionSubstances are dissolved
Mixture-Heterogeneous• Heterogeneous
mixtures have easily distinguished parts
• Ex: –Pizza
–Salsa
–Chili
Heterogeneous
ColloidScatters light
& never settles
SuspensionSeparates into layers over time
Mixture-HeterogeneousColloids scatter light & the
particles never settle• Ex: Milk, smoke, fog
Suspensions contain a liquid in which the visible particles settle
• Ex: OJ, Italian Dressing• “shake it, shake it”
Separating mixtures• Filtration – process
of separating a mixture
based on particle size
ex: coffee filter or air filter
• Distillation – the process of separating a mixture based on the boiling points of the materials
Simple Distillation
Law of Conservation of Mass
• Matter is neither created nor destroyed
• mass of all substances present before a cc=mass of all substances remaining after change
Physical Properties
characteristic of a material you can observe w/o changing substances that make up the material
Physical Properties1. Length
2. Temperature
3. Mass
4. boiling point
5. Volume
6. melting point
7. Density
8. conductivity
1. Odor
2. Texture
3. Sticky
4. Solubility
5. Stretchable
6. Luster
7. Taste
8. Magnetic
9. Malleability
10.hard/soft
Physical Changes
• change that does not alter the identity of substances in a material
Physical Changes• Ex
1. Breaking 6. Shredding
2. Pounding 7. Crushing
3. Cutting 8. Bending
4. Dissolving 9. Grinding
5. Folding 10.State Changes!?!
Chemical Properties-ability to undergo a chemical change
•Ex: Flammability is the ABILITY to burn (property)
not actually being on fire (change)
Chemical Properties
• Reacts w/ light (fading)
• Flammability
• Reacts w/ oxygen – rust or tarnish
• Reacts w/ water
• Reacts w/ acid
• Can form a precipitate
Chemical Properties-precipitates
Lead Nitrate
Copper Sulfate
PRECIPITATE VIDEO CLIPS
• http://sciencehack.com/videos/view/pFovlKpPCbI
• http://www.veoh.com/videos/v273688tMXRPJ7q
Tarnished Copper
Tarnished Silver
Rust
Chemical Changes • change of a substance into
new substances
Ex
1. Rusting
2. burning
3. Tarnishing
4. formation of a precipitate
Chemical Changes
*Signs or indicators–Fizzing
–Bubbling
–color change
Form-ing a precipitate
STAR Questions
• List some indicators of a chemical change
• Fizzing, bubbling, gas, heat, light, precipitate
• Describe difference between property and change
• Property is object’s ability to change, a change is action, it’s happening
• What type of change is evaporating?
• State changes = physical changes
________Photosynthesis________Grinding meat into hamburger________Has a sweet odor________Drying clothes on a clothesline ________Flammable________Digestion of food________Growth of a plant________Formation of clouds________Dry ice subliming________Length of 5 meters