Measurements and Significant Figures Review

Flashcards covering the fundamentals of measurement, accuracy, precision, metric conversions, SI units, and the rules of significant figures based on lecture notes.

Accuracy

The capability to measure a value that is as close as possible to the actual or true value; the degree of exactness of a measurement.

Precision

The consistency or repeatability of measurements, describing how close two or more measurements are to each other.

Systematic Errors

Errors usually caused by faulty instrumentation or faulty technique, often occurring when a series of measurements is precise but not accurate.

Measurement

The determination of the size of quantity, defined by both a quantity and a unit.

English System

A system of measurement primarily used in the United States based on various units not related by a consistent factor, such as inches, feet, and miles.

Metric System

A system of measurement used by scientists worldwide where units are always related by a factor of $10$ or a power of $10$.

Giga (G)

A metric prefix representing a factor of $10^9$ (e.g., $1\,Gg = 1,000,000,000\,g$).

Mega (M)

A metric prefix representing a factor of $10^6$ (e.g., $1\,Mg = 1,000,000\,g$).

Kilo (k, K)

A metric prefix representing a factor of $10^3$ (e.g., $1\,kg = 1000\,g$).

Deci (d)

A metric prefix representing a factor of $10^{-1}$ (e.g., $1\,dg = 0.1\,g$).

Centi (c)

A metric prefix representing a factor of $10^{-2}$ (e.g., $1\,cg = 0.01\,g$).

Milli (m)

A metric prefix representing a factor of $10^{-3}$ (e.g., $1\,mg = 0.001\,g$).

Micro ($\mu$)

A metric prefix representing a factor of $10^{-6}$ (e.g., $1\,\mu g = 0.000001\,g$).

Nano (n)

A metric prefix representing a factor of $10^{-9}$ (e.g., $1\,ng = 0.000000001\,g$).

Pico (p)

A metric prefix representing a factor of $10^{-12}$ (e.g., $1\,pg = 0.000000000001\,g$).

Meter (m)

The SI base unit for length.

Kilogram (kg)

The SI base unit for mass.

Second (s)

The SI base unit for time.

Ampere (A)

The SI base unit for electric current.

Kelvin (K)

The SI base unit for temperature.

Mole (mol)

The SI base unit for the amount of substance.

Candela (cd)

The SI base unit for luminous intensity.

Derived Units

Units based on SI base units through multiplication or division, such as density ($g/m^3$) or volume ($m^3$).

Density (\rho)

The ratio of mass to volume for a given substance, expressed as $\rho = M/V$.

Dimensional Analysis

A technique where the known quantity is multiplied by a ratio so that units cancel out to yield the desired unknown quantity.

Exact Numbers

Numbers established by definition (e.g., $12\,in = 1\,ft$) or by counting (e.g., number of passengers) that have no uncertainty.

Significant Figures

Digits in a number that carry meaningful information about its precision, including all nonzero digits and specific types of zeros.

Nonzero Digits

Digits that are always considered significant regardless of their position in a number.

Leading Zeros

Zeros in front of a decimal point or before the first nonzero digit that act only as placeholders and are not significant.

Captive Zeros

Zeros located between nonzero numbers which are always significant.

Trailing Zeros

Zeros at the end of a number that are significant if a decimal point is present, but generally assumed not significant if no decimal is shown (e.g., $28060$).

Scientific Notation

A method of writing numbers (e.g., $2.806 \times 10^4$) to avoid ambiguity regarding which trailing zeros are significant.

Water Density

A benchmark density of $1\,g/cm^3$ or $1000\,kg/m^3$, used to determine if objects will float or sink.