Chapter 1 Describing Matter

Objectives  Density  Products and Reactants  Physical Property  Chemical Property

Matter  Anything that has volume and mass

Density  A physical property of matter that compares the amount of mass in a substance to it’s volume

Why is density important?  Every element has a specific density.  If you can measure the density of an object you can determine what it’s made of.

Purity  By calculating the density of an object, you can determine how pure a substance is.

Products and Reactants  Reactants are the substances put into the reaction  Products are what are produced

Identify Products and Reactants Flour + Sugar + Eggs+ Milk A + B Pancakes C + D

 CH O 2 CO 2 + 2H 2 O

Physical Property  Determined without changing the substance  Color  Melting Point  Boiling Point

Chemical Property  Ability to react with other substances  Flammability  Ability to rust

Chemical Reaction  Changes the chemical composition of the substance  The product is a different substance from the reactant

Physical Reaction  Does not change the chemical composition of the substance  The product is the same substance as the reactant

Conservation of Mass  Mass is never created or destroyed.  The mass of the product always equals the mass of the reactant