Measurement and Chemistry Fundamentals

This set of vocabulary flashcards covers fundamental chemistry measurement concepts including units, significant figures, physical properties like density and temperature, and the distinctions between accuracy and precision.

Measurement

A collection of quantitative or numerical data that describes a property of an object or event, made by comparing a quantity with a standard unit.

Error

How much a measured value deviates from the true value.

Units

Designations that indicate the type of quantity measured.

Prefixes

Multiples of $10$ used with base units to provide scale and report quantities of any size.

Significant Figures

Digits that indicate the amount of information that is reliable when discussing a measurement; all reported digits are significant except for certain types of zeros.

SI units

The base units of science, originating from the French Système International.

Derived units

Units comprised of combinations of base units, such as $1\,J = 1\,kg\,m^{2}\,s^{-2}$.

Exact numbers

Measurements with infinite significant figures, such as discrete objects (e.g., two pennies) or exactly defined terms like metric prefixes.

Scientific Notation

A method used to write very small and very large numbers by factoring out powers of ten.

Dimensional Analysis

Also known as the factor label method, it uses a conversion factor to change a given quantity into a desired unit.

Conversion Factor

A fraction whose numerator and denominator are the same quantity expressed in different units.

Length

A measured dimension (known as the first dimension or $1D$) expressed in meters ($m$) or feet ($ft$).

Area

A two-dimensional quantity derived from the product of two lengths that expresses the extent of a figure.

Volume

A measure of the amount of space an object takes up, calculated as length cubed ($m^{3}$).

Water Displacement Method

A technique used to find the volume of an irregular solid by measuring the amount of water it pushes out of the way when submerged.

Mass

The measure of the quantity of matter contained in an object, measured using a balance.

Weight

The force that gravity exerts on an object.

Density

A unique physical property defined as the ratio of an object's mass to its volume ($\rho = m/v$).

Temperature

A measure of the average kinetic energy of the matter or system, indicating the intensity of particle energy or the flow of heat.

Celsius scale

A temperature scale developed by Anders Celsius in 1742 where $0^{\circ}C$ is the freezing point of water and $100^{\circ}C$ is the boiling point.

Fahrenheit scale

A temperature scale proposed by Daniel Gabriel Fahrenheit in 1724 where $32^{\circ}F$ is the freezing point of water and $212^{\circ}F$ is the boiling point.

Kelvin scale

An absolute thermodynamic temperature scale developed by William Thomson (Lord Kelvin) in 1848 based on absolute zero.

Absolute zero

The theoretical temperature ($0\,K$) at which all molecular motion stops and no discernable energy can be tested.

Accuracy

How close an observed value is to the true value; associated with correctness and checked by using different methods.

Precision

The reproducibility of values or the spread in values obtained from measurements, checked by repeating measurements.

Random Error

Error associated with equipment limitations that makes measurements randomly too high or too low.

Systematic Error

Error associated with procedural or equipment flaws (such as impurities) that makes measurements consistently too high or too low.