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Main Idea: What defines a physical property? Physical Properties  Matter is anything that has and takes up space.  Physical properties describe what is observed or measured.  Physical properties do not describe how the object is used.

Mass, , and Density Mass is the amount of matter something has.  This property does not change, regardless of where the object is found. Volume is the amount of space something takes up. Density is the amount of mass an object has in relation to its volume.  Density = Mass divided by Volume  Any substance will float on a liquid that has a higher density than it does. Main Idea: What is a physical change? How are physical changes recognized? Physical Changes  In a physical change, one or more properties change, but the substance stays the same.  When matter goes through a physical change the matter does not change.  Mass Conservation: No matter is created or destroyed. The amount of matter remains the same. Dissolving, Melting, and Boiling are types of physical changes.  - The ability of a substance to dissolve in a liquid  Melting - Change from a to a liquid  Boiling - Changes from liquid to a

Main Idea: What are the characteristics of a mixture? Mixtures are a combination of two or more substances.  Substances keep their original properties  The proportion of ingredients can change  The physical properties of each ingredient do not change.

Separating Mixtures keep all their original properties, it is possible to separate them.  pick them out one by one by hand  use a tool to pick them out  separate by shaking off  use a magnet to separate metals

Main Idea: What is a solution? Solutions are a type of mixture in which all substances are evenly distributed. Proportions can change.  Solubility is a measure of how much a substance will dissolve in a solvent.

Alloys are a type of mixture. Alloys are mixtures of metals.

Mixtures with Liquids  Suspensions are uniform mixtures that contains particles large enough to be seen. Don’t stay mixed.  Colloids contain particles that are too small to be seen. Stay mixed.  Emulsions are mixtures of two liquids that don’t dissolve.

McGuire 2010-2011 2

Main Idea: How are the chemical properties of a substance identified?  A chemical change is a change in which one or more new substances are formed.  A chemical property describes the ability of a substance to react with other materials and form new substances.  Both chemical and physical properties describe a substance. o A physical property describes the substance itself. o A chemical property describes how a substance reacts with other substances.

Main Idea: What is a ? Types of Reactions Molecules can combine or break up, an element in a molecule replaces an element in another molecule, or elements in molecules switch places.

Chemical Changes can be Prevented Chemical reactions can by caused by heat or exposure to air or water or exposure to ultraviolet light.

Main Idea: What are acids and bases and how are they identified? Acids and Bases react together to form water and an additional substance.  Acids turn blue litmus paper red, taste sour, and have a pH less than 7.  Bases turn red litmus paper blue, feel slippery, and have a pH greater than 7

Indicators (pg 514-515) = shows whether a substance is an acid or base  The pH scale is a measure of the strength or weakness of acids and bases.

People Use Acids and Bases  Uses of Acids = cleaning metals, manufacturing artificial silk, chemical manufacturing, electronics, and stomach acid breaks own food  Uses of Bases = water purification, dyes, and alkaline batteries.

McGuire 2010-2011