If the diameter of a carbon atom is `0.15 nm`, calculate the number of carbon atom which can be placed side by side in a straight line length of scale of length `20 cm` long.

Explanation

To solve the problem of how many carbon atoms can be placed side by side in a straight line of length 20 cm, we will follow these steps:

### Step 1: Identify the given values
- Diameter of a carbon atom = 0.15 nm
- Length of the scale = 20 cm

### Step 2: Convert units
We need to convert both the diameter of the carbon atom and the length of the scale into the same unit, preferably meters.
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