Test Your Thinking... TO BE or NOT TO BE...MELT IT! Problem: Which ice cube will melt the fastest? (A. Ice cube left on lab table B. Ice cube above a lit Bunsen burner C. Ice cube with salt applied to it D. Ice cube gently crushed with a hammer) Why? 1. Get each ice cube set up (see above list) 2. Observe and record what happens in your SsG (this should only take a couple of minutes)

Physical Change Chemical Change vs.

Physical Properties ·property that can be observed or measured without changing the composition of matter ·used to observe and describe matter APPEARANCE TEXTURE COLOR ODOR MELTING POINT/ FREEZING POINT DENSITY SOLUBILITY POLARITY MAGNETISM: Attraction (paramagnetic) / repulsion (diamagnetic) OPACITY VISCOSITY ABSORPTION VOLUME MASS MOMENTUM AREA BRITTLENESS CONCENTRATION CONDUCTIVITY FLOW RATE LENGTH LUSTER PERMEABILITY PRESSURE RADIANCE SPECIFIC HEAT VELOCITY TENSION TEMPERATURE STRENGTH SPIN ELECTRIC CHARGE

Physical Change ·there is only a change of state. ·new substance has the same properties as the old one ·NO NEW substance is produced Ex. ice--> water--> steam (yup STILL H 2 O...aka. water) ice melting to water or water boiling to steam ·may involve changing the shape of the substance Ex. paper cut into pieces (still paper) sloughing a field (but the field still remains as soil) cutting wood into pieces (still wood) molding a sculpture (still cement, marble or clay)

Chemical Properties ·DOES CHANGE the chemical nature/make-up of matter HEAT OF COMBUSTION REACTIVITY WITH H 2 O pH ELECTROLYSIS TOXICITY FLAMMABILITY OXIDATION CORROSION

Chemical Change ·one or more NEW substances are created ·new substance is different from the original ·properties are different than those of starting material ·YOU CANNOT get the ORIGINAL BACK EASILY Something to think about... A single match in a box can remain unchanged forever. But if someone were to take the match and light it...A flame lights up and then burns out. What remains will have changed FOREVER! The match can never be lighted again. The match has undergone a chemical reaction.

raw egg becomes cooked egg cake mix becomes cake paper becomes ash steel becomes rust Examples of Chemical Changes...

It might just be a chemical change IF New color appears 2. Heat or light is given off. 3. Bubbles of gas are given off 4. A precipitate is formed 5. The change is difficult to reverse