Question

Which choice correctly expresses the number below in scientific notation 0.0000431

Answer 1

Scientific notation is form $a * 10^{x}$, where 1 ≤ a < 10. So, you have to write like this:
$0.0000431 = 0.000431 * 0.1 = ... = 4.31 * 0.00001 = 4.31 * 10^{-5}$
since $0.00001 = 10^{-5}$
So, the answer is $4.31 * 10^{-5}$