Answer
$7.8\times10^{-8}$
Work Step by Step
Step 1: Scientific Notation includes only one non-zero digit in front of the decimal point.
Step 2: For $0.000000078$, the decimal point must be moved 8 times to the right in order to ensure that their is only one non-zero digit in front of the decimal point.
Step 3: Therefore, $0.000000078=7.8\times10^{-8}$.
