Matter Properties

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/cm 3, 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 g and when placed in 15.0 mL of water causes the level to rise to 22.4 mL?

CHM 1010 PGCC Barbara A. Gage

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 What were the chemical changes you encountered on Day 2? Burning of ethanol Heating CuCO 3 Reaction of cobalt chloride and sodium phosphate Burning splint Ethanol and KMnO 4

Chemical Change CHM 1010 PGCC Barbara A. Gage From Silberberg, Principles of Chemistry, 2007

Distinguishing Between Physical and Chemical Changes PROBLEM: Decide whether each of the following process is primarily a physical or a chemical change, and explain briefly: SOLUTION: (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. (a) physical change(b) chemical change(c) chemical change (d) physical change(e) chemical change