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 Substance Matter that always has same composition Mixtures Composition is not fixed

Pure Substance Matter that always has exactly same composition ex: salt sugar gold

Pure Substance Element Cannot be broken down into simpler substances Compound Made 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 (H 2 O) –Salt (NaCl) –Steam

Mixtures Heterogeneous different parts are noticeably different Homogeneous substances are uniformly distributed

Mixture-Homogeneous Homogeneous mixtures contain substances that are uniformly spread out aka: Solution Ex: Vinegar, Syrup

Homogeneous Aka: Solution Substances are dissolved

Mixture-Heterogeneous Heterogeneous mixtures have easily distinguished parts Ex: –Pizza –Salsa –Chili

Heterogeneous Colloid Scatters light & never settles Suspension Separates into layers over time

Mixture-Heterogeneous Colloids 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 Properties 1.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. Breaking6. Shredding 2. Pounding7. Crushing 3. Cutting8. Bending 4. Dissolving9. Grinding 5. Folding10.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 lKpPCbIhttp://sciencehack.com/videos/view/pFov lKpPCbI XRPJ7qhttp:// XRPJ7q

 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