Chapter 2: Properties of Matter Section 3: Properties are used to identify substances

Review Matter can physically change from one state to another. The processes of these changes include: * Melting* Freezing * Evaporation* Boiling * Condensation* Sublimation

Identifying unknown substances. You can measure the unknown substance by measuring the physical properties, such as: Heating Electric Properties Density Magnetic Properties Solubility

Magnetic Properties Some properties are attracted to magnets, but others are not. You can use magnets to separate metals from non-metals.

Electric Properties Some substances conduct electricity better than others. With proper equipment, scientists can test the electric conductivity of an unknown substance.

Density The densities of wood, plastic, and steel are all different. Scientists already determined the densities of many substances, so as a result you can compare the density of an unknown substance with the densities of a known substance.

Solubility and Heating Properties Solubility is a measure of how much a substance dissolves in a given volume of a liquid. Substances respond to heating in different ways. Some warm up quickly while others take a long time to heat up. This describe a substance’s heating property.

10 Signs of a Chemical Change 1) Bubbles/Gas Forms 2) Precipitate forms 3) Color Change 4) Temperature changes 5) Light Production 6) Volume Change 7) Electrical conductivity Change 8) Melting/boiling point Change 9) Smell/Taste Change 10) Change in any chemical/physical property

Color Change A change in color is a good indication that one substance has chemically changed into another substance.

Precipitate Formation A Precipitate is a substance that had precipitated or separated from a solution. It has chemically separated from the solution.

Bubble/Gas Formation Another sign of a chemical reaction is when bubbles are formed. Example: Baking Soda and Vinegar

Light Production When light is emitted, it is another sign of a chemical change.

color, odor, texture, density, boiling point, freezing point

B; It has physical properties like those of water, while A does not.

Some substances are attracted to magnets, while others are not. Some substances warm up quickly, while others do not.

because mass only depends on how much of the object there is, not the substance of the object directly

A magnet can be used to separate steel from aluminum. A filter can be used to separate a solid from a liquid. Evaporation can be used to separate sugar from water.

You could use a scoop with holes to pick up the nails, and the sawdust would fall through, like a kind of filter. You could use a magnet to pick up the nails.