To place the numbers in descending order, we need to compare the values of the exponents and the base numbers.
First, let's compare the exponents:
-10, -10, -12, -8
The exponents are -10, -10, -12, -8. In descending order, it will be -8, -10, -10, -12.
Next, let's compare the base numbers:
2.3, 3.2, 2.3, 2.3
Since all the base numbers are the same, we don't need to compare them further.
Now, we can arrange the numbers according to the descending order of the exponents:
2.3 × 10^-8, 2.3 × 10^-10, 3.2 × 10^-10, 2.3 × 10^-12
Final descending order: 2.3 × 10^-8, 2.3 × 10^-10, 3.2 × 10^-10, 2.3 × 10^-12