JMU Chem 120 Final Questions With Complete Solutions

scientific notation correct answer: 3.94 x 10⁷= 0. = 8.0 x 10⁻⁶ measured v. exact numbers correct answer: measured = obtained through measurement and are uncertain exact = obtained through counting and are certain precision v. accuracy correct answer: precision = close to each other accuracy = close to the actual number conversion factor correct answer: a ratio of equivalent measurements used to convert a quantity from one unit to another density correct answer: d = m/v specific gravity correct answer: SG = density of substance / density of water properties of elements correct answer: only one type of material made up of atoms properties of compound correct answer: made of 2 or more elements chemically combined in the same proportion, made up of molecules properties of a mixture correct answer: made of 2 or more substances physically combined ∙heterogenous: contains two or more phases (ex: soda, OJ) ∙homogenous: contains a uniform composition (ex: salt water) physical change correct answer: composition remains the same but state, size, or appearance change (ex: grinding chalk into a powder) chemical change correct answer: conve