Measurement and Significant Figures

Measurement is an important aspect of chemistry, and it involves the use of various units and standards to quantify physical properties such as mass, volume, temperature, and time. It is essential to use the correct units and standards in order to ensure accurate and consistent results.

Significant figures are used to express the precision of a measurement, and they represent the digits in a measurement that are known with certainty, as well as the last digit that is estimated. For example, if a measurement is reported as "123.45 g," there are 5 significant figures, since all of the digits are known with certainty. If the measurement is reported as "123.4 g," there are only 4 significant figures, since the last digit (5) is estimated.

It is important to use the correct number of significant figures when expressing measurements, and this is especially important when performing calculations. In general, the result of a calculation should be rounded to the same number of significant figures as the measurement with the least number of significant figures.