Measurement

Vocabulary

absolute zero

minimum possible temperature theoretically achievable, equal to 0 K (–273.15°C), at which there is no particle motion

accuracy

how close a measurement is to a value that is widely accepted to be the true value

balance

laboratory tool used to measure mass

Celsius temperature scale

temperature scale based on a freezing point of water of 0°C and a boiling point of water of 100°C at sea level

conversion factor

algebraic ratio between two different units

density

amount of matter contained in a given volume

dimensional analysis

technique in which the relationship between units is tracked throughout a calculation

extensive physical property

property of matter that depends on the amount of matter present

Fahrenheit temperature scale

temperature scale based on a freezing point of water of 32°F and a boiling point of water of 212°F at sea level

intensive physical property

property of matter that does not depend on the amount of matter present

International System of Units (SI)

system of units used by the global scientific community, built on seven base units: ampere, candela, kelvin, kilogram, meter, mole, and second

Kelvin temperature scale

absolute temperature scale based on the Celsius scale but shifted so that the lowest possible temperature is 0 K

mass (m)

amount of matter in an object

meniscus

curved surface of a liquid in a thin tube

precision

degree to which a measurement can be reproduced

random error

error in a measurement caused by an unknown or unpredictable source, such as an experimenter making a mistake

scientific notation

method of expressing numbers as a coefficient greater than or equal to 1 but less than 10, multiplied by 10 raised to the appropriate power

SI base unit

one of the seven fundamental units of measurements in the International System of Units

significant figures

number of digits in a measurement that are certain, plus one digit that contains some uncertainty

system of measurement

set of units in which some units are defined in relationship to other units in the system and not by a physical standard

systematic error

consistent error in measurements that leads to a precise but inaccurate measurement

true value

value that would be obtained in an ideal measurement

volume (V)

amount of space occupied by a given mass

weight (w)

measure of the force of gravity acting on an object