McGraw-Hill Science 2005

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Macmillan/McGraw-Hill Science Grade 6
Grade 6
Summary Lesson Summary
Physical Properties of Matter

Matter includes all solids, liquids, and gases. The amount of matter in an object is that objectís mass. Mass can be measured in units called grams or kilograms. Weight is the amount of force the Earthís gravity exerts on an object. Weight is measured by a balance. Objects with more mass have more weight. Volume is the amount of space taken up by an object. It is measured in cubic centimeters. The amount of mass in a given volume is an objectís density. The density of an object determines if it floats or sinks when it is placed in a liquid or a gas.

Physical properties of matter include its color, shine, hardness, and odor. Physical properties can be observed without changing the substance being observed. Another physical property of matter is its state. Matter can be a solid, liquid, or a gas. Physical changes to matter change its size, shape, or state without forming a new substance. Physical changes include tearing, cutting, melting, mixing, and evaporating.

Mixtures are combinations of two substances in which both substances keep their own properties. A suspension is a mixture made of parts that separate upon standing. Emulsions are suspensions of two liquids that usually do not mix together. Colloids are mixtures that contain undissolved particles or droplets that stay mixed in another substance. Solutions are a special kind of mixture in which one substance dissolves in another so the properties are the same throughout. Alloys are solutions of one or more metals and other solids.