Air contains about 0.03% of carbon dioxide. The concentration in parts per million is

Explanation

To find the concentration of carbon dioxide in air in parts per million (ppm), we can follow these steps:

### Step 1: Understand the given information
We are given that air contains about 0.03% of carbon dioxide. This means that in every 100 grams of air, there are 0.03 grams of carbon dioxide.

### Step 2: Convert percentage to a fraction
To convert the percentage to a fraction, we can express 0.03% as:
\[ 0.03\% = \frac{0.03}{100} \]

### Step 3: Use the formula for parts per million (ppm)
The formula for parts per million is given by:
\[ \text{ppm} = \left( \frac{\text{mass of solute}}{\text{mass of solution}} \right) \times 10^6 \]
In this case, the mass of the solute (carbon dioxide) is 0.03 grams, and the mass of the solution (air) can be assumed to be 100 grams (since we are considering the percentage).

### Step 4: Substitute the values into the formula
Now we can substitute the values into the formula:
\[ \text{ppm} = \left( \frac{0.03 \text{ grams}}{100 \text{ grams}} \right) \times 10^6 \]

### Step 5: Calculate the concentration in ppm
Now, we can perform the calculation:
\[ \text{ppm} = \left( \frac{0.03}{100} \right) \times 10^6 = 0.0003 \times 10^6 = 300 \]

### Final Answer
Thus, the concentration of carbon dioxide in air is **300 parts per million (ppm)**.

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