Significant Figures and SI Units

This set of vocabulary flashcards covers SI base and derived units, metric prefixes, accuracy vs precision rules, and the rules for determining and calculating with significant figures based on lecture notes.

Accuracy

How close the measurement is to the "true" value.

Precision

Describes how consistent measurements are.

Placeholder zero

A zero used to indicate the location of a decimal point; these are not significant.

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 Amount of substance.

Candela ($cd$)

The SI base unit for Luminous intensity.

Hertz ($Hz$)

An SI derived unit for Frequency, equivalent to $s^{-1}$.

Newton ($N$)

An SI derived unit for Force, equivalent to $m \times kg \times s^{-2}$.

Pascal ($Pa$)

An SI derived unit for Pressure, equivalent to $N/m^2$.

Joule ($J$)

An SI derived unit for Energy, equivalent to $N \times m$.

Watt ($W$)

An SI derived unit for Power, equivalent to $J/s$.

Coulomb ($C$)

An SI derived unit for Electric charge, equivalent to $s \times A$.

Volt ($V$)

An SI derived unit for Electric potential, equivalent to $W/A$.

Ohm ($\Omega$)

An SI derived unit for Electric resistance, equivalent to $V/A$.

Degree Celsius ($^{\circ}C$)

An SI derived unit for temperature that is equal in magnitude to the unit kelvin.

Tera ($T$)

An SI prefix indicating a factor of $10^{12}$ ($1,000,000,000,000$).

Giga ($G$)

An SI prefix indicating a factor of $10^9$ ($1,000,000,000$).

Mega ($M$)

An SI prefix indicating a factor of $10^6$ ($1,000,000$).

Kilo ($k$)

An SI prefix indicating a factor of $10^3$ ($1,000$).

Hecto ($h$)

An SI prefix indicating a factor of $10^2$ ($100$).

Deka ($da$)

An SI prefix indicating a factor of $10^1$ ($10$).

Deci ($d$)

An SI prefix indicating a factor of $10^{-1}$ ($0.1$).

Centi ($c$)

An SI prefix indicating a factor of $10^{-2}$ ($0.01$).

Milli ($m$)

An SI prefix indicating a factor of $10^{-3}$ ($0.001$).

Micro ($\mu$)

An SI prefix indicating a factor of $10^{-6}$ ($0.000001$).

Nano ($n$)

An SI prefix indicating a factor of $10^{-9}$ ($0.000000001$).

Pico ($p$)

An SI prefix indicating a factor of $10^{-12}$ ($0.000000000001$).

General Measurement Rule

Report all values that can be read with certainty and one estimated value, which is uncertain.

Significant Figures

Figures used to indicate the uncertainty in a measurement; this really means reporting to the appropriate level of precision.

Non-zero Rule

Any non-zero number is significant.

In-between Zero Rule

Zeroes between non-zero digits are always significant (e.g., $3,606$ has $4$ sig figs).

Decimal Point Indicator Rule

Zeroes that indicate the decimal point are not significant (e.g., $360,600$ has $4$ sig figs).

Following Decimal Rule

Zeroes following a decimal are significant (e.g., $3.60$ has $3$ sig figs).

Leading Zero Rule

Zeroes appearing before a non-zero digit are not significant (e.g., $0.009$ has $1$ sig fig).

Exact Numbers Rule

Numbers not obtained by measurement (like counted objects or definitions) have infinite significant figures.

Addition and Subtraction Rule

The answer must contain the same number of decimal places as the least accurate measurement.

Multiplication and Division Rule

The answer must contain the same number of significant figures as the least accurate measurement.