Chapter 1 - Chemical Foundations - Questions - Page 34: 21

A qualitative observation describes something through non-numerical terms. SI unit for mass: Grams SI unit for length: Meters SI unit for volume: Meters cubed The assumed uncertainty of a number is plus or minus one in the last significant digit of the number. The amount of significant figures in a measurement relies on the precision of the measuring tool. This in turn determines the uncertainty of the measurement.

A​ ​qualitative​ ​observation​ ​describes​ ​the​ ​qualities​ ​of​ ​something;​ ​for​ ​example,​ ​its texture.​ ​The​ ​SI​ ​units​ ​for​ ​mass​ ​are​ ​grams,​ ​while​ ​the​ ​SI​ ​units​ ​for​ ​length​ ​are​ ​meters.​ ​The​ ​SI​ ​units for​ ​volume​ ​are​ ​meters​ ​cubed.​ ​​The​ ​assumed​ ​uncertainty​ ​in​ ​a​ ​number​ ​is​ plus or minus one ​in​ ​the​ ​last​ ​sig​ ​fig​ ​of the​ ​number​ ​(i.e.​ ​.001​ ​grams​ ​->​ ​the​ ​assumed​ ​uncertainty​ ​from​ ​.000​ ​to​ ​.002).​ ​​The​ ​precision​ ​of​ ​a measuring tool determines​ ​the​ ​amount​ ​of​ ​sig​ ​figs​ ​in​ ​the​ ​measurement,​ ​and​ ​therefore,​ ​the uncertainty​ ​of​ ​the​ ​measurement.