The number 0.000000065 can be expressed in scientific notation as \( 6.5 \times 10^{-8} \).
To clarify:
- 0.000000065 can be rewritten as 6.5 multiplied by 10 raised to the power of -8.
- The other options you mentioned, such as \( 6.5 \times 10^{7} \) or \( 6.5 \times 10^{8} \), are incorrect representations of the original number.
So, the correct scientific notation is:
\[ 6.5 \times 10^{-8} \]