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Matter and change
- 1. Properties of MatterCentral School 8th Grade Mr. Sitz
- 2. Matter Matter is anything that: has mass takes up space Mass = a measure of the amount of “stuff” (or material) the object contains. *don’t confuse this with weight, a measure of gravity Volume = a measure of the space occupied by the object
- 3. Describing Matter Propertiesused to describe matter can be classified as: Extensive – depends on the amount of matter in the sample Mass, volume, calories are examples Intensive – depends on the type of matter, not the amount present - Hardness, Density, Boiling Point
- 4. Properties are… Wordsthat describe matter (adjectives) Physical Properties - a property that can be observed and measured without changing the material’s composition. Examples- color, hardness, m.p., b.p. Chemical Properties - a property that can only be observed by changing the composition of the material. Examples- ability to burn, decompose, ferment, react with, etc.
- 5. States of matterSolid - matter that can not flow (definite shape) and has definite volume. Liquid - definite volume but takes the shape of its container (flows). Gas - a substance without definite volume or shape and can flow. Vapor - a substance that is currently a gas, but normally is a liquid or solid at room temperature. (Which is correct: water gas, or water vapor?)
- 6. States of MatterSolid Liquid Gas Definite Volume? YES YES NO Definite Shape? YES NO NO Result of a TemperatureIncrease? Small Expanse Small Expanse Large Expanse Will it Compress? NO NO YES
- 7. 4 th state: Plasma - formed at high temperatures; ionized phase of matter as found in the sun.
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- 9. Solid Liquid Gas Melt Evaporate Condense Freeze
- 10. Copper Phases -Solid
- 11. Copper Phases -Liquid
- 12. Copper Phases –Vapor (gas)
- 13. Physical vs. ChemicalChange Physical change will change the appearance, without changing the composition of the material. Boil, melt, cut, bend, split, crack Is boiled water still water? Can be reversible , or irreversible Chemical change - a change where a new form of matter is formed. Rust, burn, decompose, ferment
- 14. Mixtures Mixtures area physical blend of at least two substances; have variable composition. They can be either: Heterogeneous – the mixture is not uniform in composition Chocolate chip cookie, gravel, soil. Homogeneous - same composition throughout; called “ solutions ” Kool-aid, air, salt water Every part keeps it’s own properties.
- 15. Solutions are homogeneousmixtures Mixed molecule by molecule, thus too small to see the different parts Can occur between any state of matter: gas in gas; liquid in gas; gas in liquid; solid in liquid; solid in solid (alloys), etc. Thus, based on the distribution of their components, mixtures are called homogeneous or heterogeneous .
- 16. Phase? The term“phase” is used to describe any part of a sample with uniform composition of properties. A homogeneous mixture consists of a single phase A heterogeneous mixture consists of two or more phases.
- 17. Separating Mixtures Somecan be separated easily by physical means: rocks and marbles, iron filings and sulfur (use magnet) Differences in physical properties can be used to separate mixtures. Filtration - separates a solid from the liquid in a heterogeneous mixture (by size)
- 18. Separation of aMixture Components of dyes such as ink may be separated by paper chromatography .
- 19. Separation of aMixture Distillation: takes advantage of different boiling points.
- 20. Substances Elements -simplest kind of matter cannot be broken down any simpler all one kind of atom. Compounds are substances that can be broken down only by chemical methods when broken down, the pieces have completely different properties than the original compound. made of two or more atoms, chemically combined (not just a physical blend!)
- 21. Compound or Mixture?Compound Mixture Made of one kind of material Made of more than one kind of material Made by a chemical change Made by a physical change Definite composition Variable composition
- 22. Which is it?Element Compound Mixture
- 23. Elements vs. CompoundsCompounds can be broken down into simpler substances by chemical means, but elements cannot . A “ chemical change ” is a change that produces matter with a different composition than the original matter.
- 24. Chemical Change Achange in which one or more substances are converted into different substances. Heat and light are often evidence of a chemical change.
- 25. Properties of CompoundsQuite different properties than their component elements. Due to a CHEMICAL CHANGE, the resulting compound has new and different properties: Table sugar – carbon, hydrogen, oxygen Sodium chloride – sodium, chlorine Water – hydrogen, oxygen
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- 27. Symbols & FormulasCurrently, there are 117 elements Elements have a 1 or two letter symbol , and compounds have a formula . An element’s first letter always capitalized; if there is a second letter, it is written lowercase: B, Ba, C, Ca, H, He Some names come from Latin or other languages.
- 28. Chemical Changes Theability of a substance to undergo a specific chemical change is called a chemical property . iron plus oxygen forms rust, so the ability to rust is a chemical property of iron During a chemical change (also called chemical reaction), the composition of matter always changes.
- 29. Chemical Reactions are…When one or more substances are changed into new substances. Reactants - the stuff you start with Products - what you make The products will have NEW PROPERTIES different from the reactants you started with Arrow points from the reactants to the new products
- 30. Recognizing Chemical ChangesEnergy is absorbed or released (temperature changes hotter or colder) Color changes Gas production (bubbling, fizzing, or odor change; smoke) formation of a precipitate - a solid that separates from solution (won’t dissolve) Irreversibility - not easily reversed But, there are examples of these that are not chemical – boiling water bubbles, etc.
- 31. Conservation of Mass During any chemical reaction, the mass of the products is always equal to the mass of the reactants. All the mass can be accounted for: Burning of wood results in products that appear to have less mass as ashes; where is the rest? Law of conservation of mass
- 32. reactants = product 43.43 g Original mass = 43.43 g Final mass