Unit 1: Measurements, Metric Conversions, and Significant Figures

Comprehensive vocabulary flashcards covering fundamental chemistry measurement principles, metric system prefixes, SI base units, significant figures rules, density, percent error, and unit conversions.

Chemistry

The branch of science that studies the composition, structure, properties, and changes of matter, as well as the energy released or absorbed during these processes.

Quantitative Measurement

A measurement that yields numerical information consisting of both a numerical value and an appropriate unit of measure.

Qualitative Measurement

A descriptive observation that provides non-numerical information regarding physical characteristics or qualities, such as color or state of matter.

Accuracy

The degree of closeness or agreement between an experimentally measured value and the true, accepted standard value.

Precision

The degree of agreement or repeatability among several independent measurements of the same quantity obtained under the same experimental conditions.

Scientific Notation

A mathematical method for expressing very large or very small numbers in the format $M \times 10^n$, where $1 \le M < 10$ and $n$ is an integer.

Significant Figures

All the reliably known digits in a measurement resulting from an instrument's calibration markings, plus one final estimated or uncertain digit.

Significant Figures: Addition and Subtraction Rule

The rule stating that the final calculated result must be rounded to the same number of decimal places as the measurement possessing the fewest decimal places.

Significant Figures: Multiplication and Division Rule

The rule stating that the final calculated answer must be rounded to contain the same total number of significant figures as the starting measurement with the fewest significant figures.

Proper Measurement Recording Rule

The procedure of recording every certain digit corresponding to the visible markings of a measuring instrument, plus one final estimated digit between marks (the only exception being digital instruments that display exact readouts).

Meniscus

The curved surface formed by a liquid in a graduated cylinder or tube, read at eye level at the lowest point of the concave curve to properly record liquid volume.

SI Base Units

The standardized fundamental units of the International System of Units: mass in kilograms ($\text{kg}$), temperature in kelvin ($\text{K}$), length in meters ($\text{m}$), time in seconds ($\text{s}$), and amount of substance in moles ($\text{mol}$).

Metric Prefixes

Systematic decimal multiples and submultiples used with base units, including kilo ($10^3$), deci ($10^{-1}$), centi ($10^{-2}$), milli ($10^{-3}$), micro ($10^{-6}$), and nano ($10^{-9}$).

Celsius to Kelvin Conversion

The temperature conversion relationship defined by the formula $K = {^\circ}\text{C} + 273$.

Density

The physical property of matter defined as the mass of an object divided by its volume: $\text{Density} = \frac{\text{Mass}}{\text{Volume}}$, commonly measured in $\text{g/mL}$ or $\text{g/cm}^3$.

Percent Error

A quantitative measure of experimental accuracy calculated as $\text{Percent Error} = \frac{|\text{Experimental Value} - \text{Accepted Value}|}{\text{Accepted Value}} \times 100\%$.

Conversion Factor

A fraction or ratio formed from two equivalent values expressed in different units that equals $1$, used in dimensional analysis (the factor-label method) to switch between measurement units.