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