Please check my answer:

Place the numbers in order of largest to smallest.

2.3 × 10−10 ; 3.2 × 10−10 ; 2.3 × 10−12 ; 2.3 × 10−8...

In order of largest to smallest, the numbers are:

3.2 × 10^-10
2.3 × 10^-10
2.3 × 10^-8
2.3 × 10^-12