Chapter 3

Any measurable aspect of something

A unit is the name and the size of a portion of a dimension that has a value of 1.

bias occurs when an observer imposes his presuppositions on the observational results.

quantitative data) or precise word descriptions (qualitative data).

quantitative data) or precise word descriptions (qualitative data).

is officially called the International Prototype Kilogram (IPK).

SI base units have their own unit symbols and can’t be expressed as combinations of any other SI units.

are combinations of the SI base units.

evaluates how close a measurement is to the acceptable value of the measurement.

evaluates how exactly a measurement is made.

Scientists evaluate the usefulness of their measurements by repeating them as many times as needed to see how they vary

• Property of matter used to identify certain substances when you measure them under standard conditions

Can indicate the amount of matter in an object—but does not measure the amount of matter directly

the measure of the amount of matter in an object

• All matter occupies space • Volume—space enclosed or occupied by an object • Rectangular solid: volume = length × width × height