Dr. M. J. Passow  INTERMEDIATE LEVEL SCIENCE
Physical Setting Key Idea 3:  Matter is made up of particles whose properties determine the observable characteristics of matter and its reactivity.
3.1  Observe and describe properties of materials, such as density, conductivity, and solubility.
Core Concepts	Suggested Activity
3.1a  Substances have characteristic properties.  Some of these include: color, odor, phase at room temperature, density, solubility, heat and electrical conductivity, hardness, and boiling and freezing points.
3.1b  Solubility can be affected by temperature, surface area, stirring, and pressure.
3.1c  The motion of particles helps to explain the phases (states) of matter, as well as changes from one phase to another.  The phase at which matter exists depends on the attractive forces among its particles.
3.1d  Gases have neither a determined shape nor a definite volume.  Gases assume the shape and  volume of a closed container.
3.1e  A liquid has definite volume, but takes the shape of its container.
3.1f  A solid has definite shape and volume.  Particles resist a change in position.
3.1g  Characteristic properties can be used to identify different materials, and separate a mixture of substances into its components.  For example, iron filings can be removed from a mixture by means of a magnet.  An insoluble substance can be separated from a soluble substance by such processes as filtration, settling, and evaporation.
3.1h  Density can be described as the amount of matter that is in a given amount of space.  If two objects have equal volume, but one has more mass, the one with more mass is denser.
3.1i  Buoyancy is determined by comparative densities.
3.2  Distinguish between chemical and physical changes.
Core Concepts	Suggested Activity
3.2a  During a physical change, a substance keeps its chemical composition and properties.  Examples of physical changes include freezing, melting, condensation, boiling, evaporation, tearing, and crushing.
3.2b  Mixtures are physical combinations of materials and can be separated by physical means.
3.2c  During a chemical change, substances react in characteristic ways to form new substances with different physical and chemical properties.  Examples of chemical changes include burning, cooking, rusting of iron, and souring of milk.
3.2d  Substances are often placed in categories if they react in similar ways.  Examples include metals, nonmetals, and noble gases.
3.2e  The "Law of Conservation of Mass" states that during an ordinary chemical reaction, matter cannot be created or destroyed.  In chemical reactions, the total mass of the reactants equals the total mass of the products.
3.3  Develop mental models to explain common chemical reactions and changes in states of matter.
Core Concepts	Suggested Activity
3.3a  All matter is made up of atoms.  Atoms are far too small to see with a light microscope.
3.3b  Atoms and molecules are perpetually in motion.  The greater the temperature, the greater the motion.
3.3c  Atoms may join together in well-defined molecules or may be arranged in regular geometric patterns.
3.3d  Interactions among atoms and/or molecules result in chemical reactions.
3.3e  The atoms of any one element are different from the atoms of other elements.
3.3f  There are more than 100 elements.  Elements combine in a multitude of ways to produce compounds that account for all living and nonliving substances.  Few elements are found in their pure form.
3.3g  The periodic table is one useful model for classifying elements.  The periodic table can be used to predict properties of elements (metals, nonmetals, noble gases).