Chapter 3: Measurements and Calculations

Measurement

A quantitative observation

Unit

The part of the measurement telling us the scale of being used.

Scientific Notation

Expressing a number in the form of N x 10M: a convenient method for representing a very large or very small number and for easily indicating the number of significant figures.

Metric System

A decimal-based measuring system.

International system (SI)

A standardized unit system based on the metric system is used globally; the most commonly used system of scientific measurement.

Volume

The amount of three-dimensional space occupied by a substance.

Meter

The base SI unit of length.

Liter

The fundamental unit of volume in the SI system, equal to 1 cubic decimeter.

Mass

The quantity of matter in an object.

Kilogram

The base SI unit of mass.

Conversion factor

A ratio used to convert from one unit to another.

Significant figures

The certain digits and the first uncertain digit of a measurement.

Equivalence statement

The relationship between measurements in different units that measure the exact same quantity.

Dimensional analysis

The process of using conversion factors to change from one unit to another.

Fahrenheit scale

A temperature scale on which water freezes at 32 degrees and boils at 21 degrees.

Celsius scale

A temperature scale based on powers of 10 on which water freezes at 0 degrees and boils at 100 degrees, most commonly used for scientific measurement.

Kelvin (absolute) scale

(absolute scale) a temperature scale on which 0 K is absolute zero, water freezes at 273K, and water boils at 373K; the kelvin is the Si unit of temperature.

Density

The mass of substance per a given volume of that substance.

Specific Gravity

The ratio of density of a given liquid to the density of water at 4 degrees Celsius.