## The concentration of Sodium Fluoride in a community’s drinking water is 0.6ppm.express this concentration as a percentage:

**a-**0.00006%*****b-**0.0006%**c-**0.006%**d-**0.06%**e-**0.6%

### The correct answer is a. 0.00006%.

To convert ppm (parts per million) to a percentage, you need to multiply the ppm value by 0.0001. In this case, 0.6 ppm x 0.0001 = 0.00006%.

#### The other options are incorrect:

**b. 0.0006%**would be the result of multiplying 0.6 ppm by 0.001, which is equivalent to 1 ppm.**c. 0.006%**would be the result of multiplying 0.6 ppm by 0.01, which is equivalent to 10 ppm.**d. 0.06%**would be the result of multiplying 0.6 ppm by 0.1, which is equivalent to 100 ppm.**e. 0.6%**would be the result of dividing 0.6 ppm by 10, which is equivalent to 60 ppm.