Question

count the significant digits in each of these measurements:
\begin{tabular}{|l|l|}hline measurement & number of significant digits \hline 0.009300 j & \hline - 2.0×10⁻³ kj/mol & \hline 69400. kg & \hline 9.6×10⁻¹ ml & \hlineend{tabular}

Explanation:

Step1: Recall significant - digit rules

Non - zero digits are always significant. Leading zeros (zeros before non - zero digits) are not significant. Trailing zeros after a non - zero digit and after a decimal point are significant.

Step2: Analyze 0.009300 J

The leading zeros are not significant. The non - zero digits 9, 3 and the two trailing zeros are significant. So there are 4 significant digits.

Step3: Analyze - 2.0×10⁻³ kJ/mol

The non - zero digit 2 and the trailing zero after the decimal point are significant. So there are 2 significant digits.

Step4: Analyze 69400. kg

The decimal point indicates that the trailing zeros are significant. So there are 5 significant digits.

Step5: Analyze 9.6×10⁻¹ mL

The non - zero digits 9 and 6 are significant. So there are 2 significant digits.

Answer:

measurement	number of significant digits
- 2.0×10⁻³ kJ/mol	2
69400. kg	5
9.6×10⁻¹ mL	2