Chapter 1-6: Sig Figs and Measurement (Introduction to Sig Figs)

Vocabulary flashcards covering sig figs, accuracy, precision, reading measurements, and related concepts from the lecture notes.

Significant figures (sig figs)

Digits in a measurement that carry meaning about precision; the last digit is an estimate and may vary.

Accuracy

How close a measurement is to the true or accepted value.

Precision

The degree of reproducibility or how consistently measurements cluster when repeated.

Reproducibility

The consistency of measurements under unchanged conditions or with the same procedure.

Last digit (uncertain digit)

The final reported digit in a measurement that is estimated and can vary; indicates the measurement’s uncertainty.

Smallest marking

The finest division on a measuring instrument; determines how many sig figs you can report (you estimate beyond this).

Eye level reading

Reading a measurement at eye level to avoid parallax and ensure accuracy.

Meniscus

The curved surface of a liquid in a graduated cylinder; read at the bottom of the curve for volume.

Range

The spread of measured values across trials; a smaller range indicates higher reproducibility.

Instrument-based sig figs

The number of sig figs you report is dictated by the instrument’s markings, not by the observer’s ability.

Zeros in sig figs

Zeros are tricky: nonzero digits are always significant; zeros between nonzero digits are significant; leading zeros are not necessarily significant.

Five sig figs example

A measurement like 645.21 g has five significant figures, illustrating how digits and decimal placement determine sig figs.

Last-digit estimation rule

If a measurement lies between markings, the last digit is estimated and represents the uncertainty.

Plus/minus uncertainty

Measurements are often written as value ± uncertainty (e.g., 12.34 ± 0.05) to show the last digit’s possible variation.