Properties & Changes of Matter

What is a property of matter? Characteristic of that type of matter Can be physical or chemical property Can be observed using your senses Cannot be observed with senses- must be tested or reacted with something

Physical Properties Examples: mass, color, shape, smell, volume, density, melting point, boiling point, and hardness.

Chemical Properties Examples: ability to burn, ability to decompose (food), ability to rust, how it reacts with other substances

Changing Matter Matter can be changed two ways: Physically Chemically

Physical Changes Nothing new or different is formed Do NOT CHANGE THE IDENTITY OF MATTER on a chemical level Nothing new or different is formed Could be a change in: state shape color size Volume, Density, Mass

Examples of Physical Changes Boiling Freezing Evaporation Dissolving Breaking Cutting Painting Making a mixture 2 or more substances physically mixed together. Can be separated physically

Chemical Changes A chemical reaction MUST take place! Matter changes at the atomic level (atoms separate and recombine in different ways!). NEW SUBSTANCES are created!!!

Chemical Changes Rusting Burning Molding Cooking Mixing acids & bases Food being metabolized in body (*where??) Baking Explosion of fireworks

Law of Conservation of Mass Atoms are just rearranged, NOT created or destroyed Mass is conserved  total amount of atoms cannot change Nothing is ever created or destroyed!

Practice Problem Susie adds 10g of sodium to 15g of chlorine. How much NaCl should be present after the reaction, according to the Law of Conservation of Mass?

REMEMBER! Compounds- made of up DIFFERENT types of atoms only. (ex: H2O, CO2 but not H2!)

Law of Conservation of Mass…?!!?!