To convert the number 0.000681 into scientific notation, follow these steps:
1. Identify the decimal point in the number 0.000681.
2. Move the decimal point to the right until the number is between 1 and 10. In this case, you move the decimal point four places to the right to get 6.81.
3. For each place you move the decimal point to the right, decrease the exponent by 1. Since we moved it four places to the right, the exponent will be -4.
Combining these, the scientific notation of 0.000681 is [tex]\( 6.81 \times 10^{-4} \)[/tex].
Therefore, the correct answer is:
C. [tex]\( 6.81 \times 10^{-4} \)[/tex]
