Classification of Matter Quick Review Classification of Matter www.middleschoolscience.com 2008 Modified by LRJ 2017

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

Atoms Elements The building blocks of Matter Consists of Protons (+), Electrons (-), and Neutrons (N). Elements Consists of only one kind of atom, Cannot be broken down into a simpler type of matter by either physical or chemical means Can exist as either atoms or molecules. Images are from http://www.chem4kids.com

Molecules A molecule consists of two or more atoms of the same element, or different elements, that are chemically bound together. In the animation above, two nitrogen atoms (N + N = N2) make one Nitrogen molecule .

Compounds Atoms of two or more different elements bound together. Can be separated into elements chemically, but not physically. In the animation above, water (H20) is a compound made of Hydrogen and Oxygen. Animated images and notes from http://www.chem.purdue.edu/gchelp/atoms/elements.html

Mixtures A mixture is the physical combination of 2 or more substances meaning they are substances held together by physical forces, not chemical. 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

Homogeneous (Solutions) A homogeneous mixture is a mixture that is evenly distributed. Homogeneous mixtures are commonly called solutions. Uniform Distribution. Example: Sugar and Water Images are from http://www.chem4kids.com

Solute Solvent The substance to be dissolved. The one doing the dissolving. Images are from http://www.chem4kids.com

Making a Solution

Colloids Particle sizes are in between the size of particles found in solutions and suspensions . Can be mixed and remain evenly distributed without settling out.

Heterogeneous Mixtures A heterogeneous mixture is a mixture that is unevenly distributed. Can be separated physically. 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 Images are from http://www.chem4kids.com

Mixtures Suspensions Are heterogeneous mixtures consisting of parts that are visible to the naked eye. Substances will settle over time. Example: the ingredients in salad dressing

Classifying Matter Matter Pure Substances Mixtures Elements Compounds Homogeneous Heterogeneous Elements Compounds milk, tea, air, kool-aid, alloy butter pecan ice cream, muddy water, salad, oil/vinegar Fe, Na, Cu, I H2O, CO2, NaCl, CuSO4

Matter Pure Substances Element Compounds Molecules Mixtures Homogeneous Solution Solvent Colloids Heterogeneous Suspensions