Matter Properties http://z.about.com/d/chemistry/1/0/x/c/transitionmetalsolns.jpg
So What is Matter? • Anything that occupies space and has mass What isn’t matter? • Energy • Ideas, gravity, shadows…
Properties • Physical Property - any property that can be observed without transforming the substance into another substance mass, color, freezing point • Chemical Property - any property that cannot be studied without transforming the substance into a different substance iron rusts, paper burns
Properties • Intrinsic property– does not depend on the amount of material you have color, solubility, viscosity, malleability, boiling point • Extrinsic property – depends on the amount of matter mass, volume, length What is density?
Density • Property derived from two measurements, mass and volume • Density = Mass/Volume • Will have a unit that contains both mass and volume such as g/cm3, lb/gal, kg/L • Does not depend on the size of the sample
Density • What is the density of a sample of metal that has a mass of 34.58 g and when placed in 15.0 mL of water causes the level to rise to 22.4 mL?
Changes • Physical Change - change that does not transform the substance into another substance melting, subliming, dissolving
Physical Changes • What were the physical changes that you encountered in the activities on Day 2? Splint broken into pieces NaCl dissolved in water Sand and salt mixed Alum heated and cooled
Changes • Chemical Change -change that transforms one substance into another substance burning, oxidation of metal precipitation of solid
Chemical Changes • Whatwere the chemical changes you encountered on Day 2? Burning of ethanol Heating CuCO3 Reaction of cobalt chloride and sodium phosphate Burning splint Ethanol and KMnO4
Chemical Change From Silberberg, Principles of Chemistry, 2007 CHM 1010 PGCC Barbara A. Gage
PROBLEM: Decide whether each of the following process is primarily a physical or a chemical change, and explain briefly: Distinguishing Between Physical and Chemical Changes (a) Frost forms as the temperature drops on a humid winter night. (b) A cornstalk grows from a seed that is watered and fertilized. (c) Dynamite explodes to form a mixture of gases. (d) Perspiration evaporates when you relax after jogging. (e) A silver fork tarnishes slowly in air. SOLUTION: (a) physical change (b) chemical change (c) chemical change (d) physical change (e) chemical change