Unit 2 Matter Lesson 1

Compounds and Mixtures

Classifying Matter Matter Pure Substances Mixtures Homogeneous Heterogeneous Elements Compounds Rocky Road ice cream, muddy water, smog Kool-aid, air, brass Fe, O₂ H2O, CO2

What is a Pure Substance? A pure substance is a classification of matter that includes both elements and compounds Pure substances cannot be separated by physical means such as distillation, filtration, or chromatography.

What is an Element? An element is a form of matter made only of one type of atom Ex: Oxygen , carbon, nitrogen, gold Found on the periodic table

What Is A Compound? A compound is a pure substance that is created by 2 or more elements chemically reacting and bonding together Ex: NaCl, H2O, CO2, NH3, NaHCO3, and C6H12O6 Notice that elements combine in many ways to make compounds Ex: H2O, H2O2, CO, and CO2

What Is A Mixture? A mixture is the physical combination of 2 or more substances It is important to understand that a mixture is not chemically combined Mixtures can be separated by physical means such as filtration, distillation, and chromatography Mixtures can be divided into 2 groups Homogenous mixtures Heterogeneous mixtures

What Is a Homogenous Mixture? A homogeneous mixture is a mixture that is evenly distributed. The particles are spread out evenly throughout the mixture. Homogeneous mixtures are commonly called solutions.

What Is a Heterogeneous Mixture? A heterogeneous mixture is a mixture that is unevenly distributed Examples: Iced tea: The ice is floating at the top and therefore is not evenly distributed throughout the tea Chex Mix: You may find a different number of pretzels or Chex cereal in each handful; therefore, the mixture is unevenly distributed