To determine the number of significant figures in the measurement [tex]$5.00 \times 10^{-3}$[/tex] moles, we need to analyze the digits in the given number carefully.
1. Identify the digits in the measurement: The given measurement is [tex]$5.00 \times 10^{-3}$[/tex] moles. This can also be written in standard form as 0.00500 moles.
2. Evaluate each digit:
- The digit '5' is a non-zero digit, which is always significant.
- The zeros after the decimal point (the two zeros after the 5) are also significant because they are trailing zeros following a non-zero digit and are to the right of the decimal point.
3. Count the total significant digits:
- '5' is significant.
- The first '0' after the decimal (right after '5') is significant.
- The second '0' after the decimal (immediately following the first '0') is also significant.
So, the measurement [tex]$5.00 \times 10^{-3}$[/tex] moles contains exactly 3 significant figures.
Therefore, there are 3 significant figures in the measurement [tex]$5.00 \times 10^{-3}$[/tex] moles.
