1 micron is

Options

A. 1/100 mm
B. 1/1000 mm
C. 1/10000 mm
D. 1/100,000 mm

Explanation

To solve the question "1 micron is", we need to convert micron into millimeters and identify the correct option from the given choices.

### Step-by-Step Solution:

1. **Understand the Definition of Micron**:
- A micron (or micrometer) is defined as \(1 \mu m = 10^{-6} \text{ meters}\).

2. **Convert Meters to Millimeters**:
- We know that \(1 \text{ millimeter} = 10^{-3} \text{ meters}\).
- To convert microns to millimeters, we can use the relationship:
\[ 1 \text{ micron} = 10^{-6} \text{ meters} = \frac{10^{-6}}{10^{-3}} \text{ millimeters} \]
- This simplifies to:
\[ 1 \text{ micron} = 10^{-6 + 3} \text{ millimeters} = 10^{-3} \text{ millimeters} \]

3. **Express in Fractional Form**:
- Since \(10^{-3} \text{ millimeters} = \frac{1}{1000} \text{ millimeters}\), we can conclude:
\[ 1 \text{ micron} = \frac{1}{1000} \text{ millimeters} \]

4. **Identify the Correct Option**:
- From the options given:
- Option 1: \( \frac{1}{100} \text{ millimeters} \)
- Option 2: \( \frac{1}{1000} \text{ millimeters} \)
- Option 3: \( \frac{1}{10,000} \text{ millimeters} \)
- Option 4: \( \frac{1}{100,000} \text{ millimeters} \)
- The correct option is **Option 2: \( \frac{1}{1000} \text{ millimeters} \)**.

### Final Answer:
1 micron is \( \frac{1}{1000} \text{ millimeters} \).