Matter

1. Matter Properties and changes Chapter 2

2. Four Phases of Matter • Solids • Have definite shape and volume • Have strong intermolecular forces between particles. Therefore, the particles are very close to each other • Usually the most dense phase • In most cases incompressible

3. Four Phases of MatterLiquid 2. Liquids • Have definite volume • Takes the shape of the container • “flow” and are incompressible • The intermolecular forces are intermediate • Weaker than solids, but stronger than gases • Therefore the densities are average

4. Four Phases of MatterGases • Gases • Have no definite shape volume( dependent upon the container they fill) • Very weak intermolecular forces so they have very low densities • They are compressible and gases “diffuse”

5. Four Phases of MatterPlasma • Plasma • Energy is very high due to extremely high temperatures. • Atoms are stripped of their electrons • They are “ionized” • Moves quickly and unevenly • Examples • Sun and lightening

6. Classification of Matter • Matter • Anything that has mass and takes up space. • Pure substance • Has a constant, invariable composition • It’s identified by a formula or a symbol • Examples • Water • Helium

7. Classification of Matter • Compound • Composed of two or more elements that cannot be decomposed by physical means • Chemically combined • Examples • Sodium chloride • Carbon dioxide

8. Classification of Matter • Element • Simple substance that cannot be decomposed into simpler substances by any chemical change.

9. Classification of Matter • Mixtures • Composed of 2 or more components that can be separated by physical means • There are no chemical bonds between the separate parts • The components or parts can vary in composition • 2 types of mixtures

10. Classification of Matter • Homogeneous Mixture • Sometimes called solutions • Are evenly mixed • Appears as one component even though there are 2 or more parts • Examples • Plain jello • Air • Salt water

11. Types of mixtures • Heterogeneous mixture • Unevenly mixed • Can see separate components • Examples • Dirt • Concrete • Muddy water

12. Heterogeneous MixturesColloid vs. Suspensions • 1) Colloids • Particles are very small • Do not settle out of solution • Examples • Fog • Smoke • Whipped cream • Suspensions • Particles are large • Settle out of solution • Example: muddy water

14. Physical Separation of Mixtures Technique • 1. Filtration-to separate by size • Use filter paper and funnel • Used for homogeneous mixtures • Ex. Muddy water

15. Physical Separation of Mixtures Technique • 2. Evaporation-boiling off liquid • Used for homogeneous solutions • Example: sea water • 3. Decant-to pour off liquid • Used for homogeneous mixture

16. Physical Separation of Mixtures Technique • 4. Distillation-separate a mixture of liquids by boiling points • How is this possible? • 5. Chromatography-to separate pigments from a homogenous solution • Pigments separate because of difference in • Mass • Absorption rate

17. Physical Separation of Mixtures Technique • 6. Crystallization • Formation of solid particles of a substance from a solution containing the dissolved substance. • What does that mean? • Example • Dissolve sugar into water • Place a string into solution • What forms around the string?

19. Conservation Laws • Law of Conservation of Matter • Matter is neither created or destroyed • In reaction = • Amounts of reactants = amount of products made • Law of Conservation of Energy • Energy is neither created or destroyed BUT is rater it is transferred from one form to another

20. Physical Properties • Properties that don’t involve a change in the chemical identity of the substance • Can measure these properties/characteristics without changing the identity • Examples: • Melting point • Boiling point • Density • Electrical conductivity • solubility

21. Physical Properties Extensive Properties Intensive Properties • Extensive Properties • Dependent upon the amount of substance present • Examples: • Mass • Length • volume • Intensive properties • Independent of the amount of substance present • Examples • Density • Boiling Point

22. Chemical Properties • Chemical Properties • Refers to the way a substance undergoes a chemical reaction to form a new product. • When you measure this property (characteristic) at least one new product is formed. • Examples: the ability to rot, rust, burn, ferment, grow, decay, sprout, combust

23. Physical Change • Physical change • A process that will alter a substance’s appearance without changing its composition or idenity. • Any change that describes a • Phase Change • Melting, freezing, evaporating, condensing • Size Change • Tearing, breaking, expanding, dissolving • Shape Change • Hammering, stretching

24. Chemical Change • Chemical change • A process that occurs that will change the identity and composition of the reactants • Examples: Burning, rusting, Exploding

25. Difference between properties and changes Properties Changes Measure a characteristic or trait. Measure a process

26. Observations that Determine a Chemical change in a Lab • Gas is released • Bubbles in liquids, smoke, odor • Heat is absorbed or released • Precipitate (solid) is formed in a homogeneous solution • Start as a liquid, then you see “things” floating or settled on the bottom

27. Observations that Determine a Chemical change in a Lab • Definite color change occur • Color is a ___________ property • The process of changing colors is a chemical change • Flash of light is released.