Significant Figures in Measurements

How do you determine the number of significant figures in a measurement?

Options: 0.0460, 1.234, 100, 2.5000, 0.000605

Answer:

The number of significant figures in a measurement is determined by counting all the digits that are known with certainty plus one digit that is estimated. For each option provided:

a. 0.0460 has 3 significant figures

b. 1.234 has 4 significant figures

c. 100 has 1 significant figure

d. 2.5000 has 5 significant figures

e. 0.000605 has 3 significant figures

Explanation:

Significant figures are the digits in a number that carry meaning contributing to its precision. Zeros are used as placeholders and may or may not be considered significant depending on their placement. When counting significant figures, follow these rules:

- All non-zero digits are significant. (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9)

- Zeros between non-zero digits are significant. (e.g., 1.234 has 4 significant figures)

- Leading zeros (zeros to the left of the first non-zero digit) are not significant. (e.g., 0.0460 has 3 significant figures)

- Trailing zeros (zeros to the right of the last non-zero digit and after the decimal point) are significant. (e.g., 2.5000 has 5 significant figures)

- Trailing zeros before a decimal point are significant if they are explicitly stated to be significant. (e.g., 100 has 1 significant figure)

- Zeros that merely serve as placeholders are not considered significant. (e.g., 0.000605 has 3 significant figures)