Mr. Z's Science Notes

What are physical and chemical changes?   Lesson Review
  1. What is the difference between a physical change and a chemical change?
  2. Are volume and density chemical properties?
  3. Iron rusting is an example of a _____ change.
  4. Water freezing is and example of a ______ change.
  5. Mixing vinegar and baking soda produces carbon dioxide, what type of change is that?
  6. Are these physical or chemical changes:  Match burns, glass breaks, iron rusts, ice melts, stretching a rubber band, stretching Mr. Z's patience, crushing a sugar cube, putting sugar in water

 

Chemical vs. Physical Changes (& Atoms)

Chemical vs Physical Change

 Key Idea 3:  Matter is made up of particles whose properties determine the observable characteristics of matter and its reactivity.

 Performance Indicator 3.2:   Distinguish between chemical and physical changes.

 Major Understandings:

 3.2a During a physical change a substance keeps its chemical composition and proper-

ties. 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 of wood, cooking of an egg, 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