A student measures the volume of a liquid and finds it to be 40 mL. How many significant figures are in the measurement?
A.1
B.2
C.3
D.4
Is the answer B?
yes. did the had the same question;)
To determine the number of significant figures in a measurement, we follow a few rules:
1. Non-zero digits are always significant. In this case, the measurement is 40 mL, so both the 4 and the 0 are significant.
2. Leading zeros (zeros before any non-zero digit) are not significant. In this case, there are no leading zeros.
3. Captive zeros (zeros between non-zero digits) are always significant. In this case, the 0 is between the 4 and the mL, so it is significant.
4. Trailing zeros (zeros after the last non-zero digit) may or may not be significant, depending on whether they have been measured or are simply placeholders. To determine their significance, we need to know whether they have been measured or not. If the volume measurement is exactly 40 mL, then the trailing zero is significant. However, if the measurement is rounded to 40 mL (meaning it could be 39.5 mL or 40.4 mL, for example), then the trailing zero is not significant.
Since we don't have enough information about whether the measurement is exact or rounded, we cannot determine the significance of the trailing zero. Therefore, we cannot include it in the count of significant figures.
Based on the information given, the measurement of 40 mL has 2 significant figures. Therefore, the correct answer is B.