The velocity of a particle measured from an instrument is 0.00204300 `m//s`. The number of significant figures is

Options

A. 8
B. 4
C. 6
D. 3

Answer

To determine the number of significant figures in the velocity measurement of a particle, which is given as \(0.00204300 \, \text{m/s}\), we will follow the rules of significant figures.

### Step-by-Step Solution:

1. **Identify Leading Zeros**:
- The number \(0.00204300\) has leading zeros (the zeros before the first non-zero digit). According to the rules of significant figures, leading zeros are **not significant**.
- Therefore, we can ignore the leading zeros: \(0.00204300\) reduces to \(0.204300\).

2. **Count Non-Zero Digits**:
- The non-zero digits in the number \(0.204300\) are \(2\), \(4\), and \(3\).
- These digits are significant. So far, we have counted **3 significant figures** from the non-zero digits.

3. **Identify and Count Zeros Between Non-Zero Digits**:
- The zero between \(2\) and \(4\) (the zero in \(204300\)) is significant because it is between two non-zero digits.
- This adds **1 more significant figure** to our count.

4. **Count Trailing Zeros**:
- The two zeros at the end of \(204300\) are trailing zeros. According to the rules, trailing zeros in a decimal number are also considered significant.
- Thus, we add **2 more significant figures** for the trailing zeros.

5. **Total Count of Significant Figures**:
- Now, we can sum up all the significant figures:
- From non-zero digits: **3**
- From the zero between non-zero digits: **1**
- From trailing zeros: **2**
- Total significant figures = \(3 + 1 + 2 = 6\).

### Conclusion:
The total number of significant figures in the measurement \(0.00204300 \, \text{m/s}\) is **6**.

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