To place the numbers in descending order, we first need to compare them by their exponents. The larger the exponent in a scientific notation, the larger the number.
Here are the numbers you provided:
- \( 2.3 \times 10^{-10} \)
- \( 3.2 \times 10^{-10} \)
- \( 2.3 \times 10^{-12} \)
- \( 2.3 \times 10^{-8} \)
Now, let's compare them:
- \( 2.3 \times 10^{-8} \) has the largest exponent (-8), so it is the largest number.
- Next, we compare \( 2.3 \times 10^{-10} \) and \( 3.2 \times 10^{-10} \). Since \( 3.2 \) is greater than \( 2.3 \) but both have the same exponent (-10), \( 3.2 \times 10^{-10} \) is the next largest.
- \( 2.3 \times 10^{-10} \) comes next.
- Finally, \( 2.3 \times 10^{-12} \) has the smallest exponent (-12), so it is the smallest number.
Putting this together, the numbers in descending order are:
- \( 2.3 \times 10^{-8} \)
- \( 3.2 \times 10^{-10} \)
- \( 2.3 \times 10^{-10} \)
- \( 2.3 \times 10^{-12} \)