Chapter 2 Section 2

Can be observed or measured without changing the identity of the substance Examples Thermal Conductivity: the ability to transfer thermal energy from one area to another State: the physical form in which a substance exists Malleability: the ability to be pounded into thin sheets

Examples, continued Ductility: the ability to be drawn or pulled into a wire Solubility: the ability to dissolve in another substance Density: mass per unit volume

Is a characteristic property: can be used to help identify the substance DV M

Density differences will cause liquids to separate. Densest layer will go to the bottom Least dense will float on top See page 46

Describes a substance based on its ability to change into a new substance Examples: Flammability: ability to burn Reactivity with oxygen (oxidation) Reactivity with water Reactivity with acid

Properties that are always the same whether the sample is large or small Helps to identify a substance because they never change Example Density Solubility Reactivity with acids

A change that affects one or more physical properties of a substance Often easy to undo Examples Cutting down a tree Painting a house Melting butter Making an aluminum foil ball

When one or more substances are changed into a new substance with new properties Most chemical changes can not be undone Examples Soured milk Camp fire Rusting car Baking cookies

Color change Fizzing or foaming (gas formed) Heat (energy change) Sound (energy change) Light (energy change) Odor Precipitate- solid formed in a solution

Properties- the substances ability to go through a chemical change Changes- the actual process in which a substance changes into another substance Observe chemical properties when a chemical change might occur