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Intro to Chemistry. -States of matter -State changes -Properties of matter -Solution chemistry. What are the three states of matter?. Solids Liquids Gases (fourth state exists on the sun’s surface – known as plasma). Solid characteristics. Have a definite shape
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Intro to Chemistry -States of matter -State changes -Properties of matter -Solution chemistry
What are the three states of matter? • Solids • Liquids • Gases • (fourth state exists on the sun’s surface – known as plasma)
Solid characteristics • Have a definite shape • Have a definite volume • Particles tightly packed • Particles move minimally, but do move = vibrate in place • Two varieties: • Crystalline solids – have an ordered 3-D arrangement that is perfect, known as a crystal lattice • Amorphous solids – do not have an ordered arrangement, imperfectly packed
Liquid characteristics • Have a definite volume • Do not have a definite shape (take that of the container) • Particles real close together • Particles move relatively well • Two special properties: • Surface tension – force that determines droplet shape & form • Viscosity – property that is a rate of a liquids resistance to flow
Gas characteristics • Have no definite shape • Have no definite volume • Particles take the shape of their container and are sparse • Particles move very fast • Greatly affected by: -temperature -pressure
http://phet.colorado.edu/simulations/sims.php?sim=States_of_Matterhttp://phet.colorado.edu/simulations/sims.php?sim=States_of_Matter
How do you change from one state of matter to another? Answer: there must be a loss or gain of heat
State change terms: • Melting – solid to liquid • Freezing – liquid to solid • Evaporation – liquid to gas • Condensation – gas to liquid • Sublimation – solid to gas (jumps a state) • Endothermic reactions – gain heat energy • Exothermic – heat energy removed
What’s the difference between chemical and physical properties? • Physical properties • Magnetism • Conductivity • Density • Malleability • Solubility • State • Ductility • Boiling/melting points • Chemical properties • Reactivity • Flammability • Precipitate • Electrolysis • composition
How can you tell the difference between chemical & physical changes? • Physical changes are observable and measurable. • Chemical changes are a substances ability to undergo a chemical reaction and come out chemically different, or altered.