Reference library3 entries

Category: Exact Numbers

Understanding exact numbers that have infinite significant figures.

Why Is a Mole Exact? The Difference Between a Count and a Measurement in Chemistry

The mole is exact because the SI defines it by an exact fixed value of the Avogadro constant; however, most laboratory amounts are obtained…

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Counted Numbers vs Measured Numbers: Precision and Significant Figures

Counted numbers are exact and have infinite significant figures, while measured numbers carry uncertainty and are limited by the instrument's precision. This guide explains…

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Exact Numbers Have Infinite Significant Figures — Here’s What That Means

Exact numbers, such as counted quantities and defined conversion factors, possess an infinite number of significant figures. This article explains the rule, provides worked…

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