To place the numbers in descending order, we first need to express them in a common format for comparison. The numbers are:
- \( 2.3 \times 10^{-10} \)
- \( 3.2 \times 10^{-10} \)
- \( 2.3 \times 10^{-12} \)
- \( 2.3 \times 10^{-8} \)
We compare them by looking at the exponent first. The higher the exponent, the larger the number when the base is the same.
- \( 2.3 \times 10^{-8} \) (exponent = -8)
- \( 2.3 \times 10^{-10} \) (exponent = -10)
- \( 3.2 \times 10^{-10} \) (exponent = -10; it's larger than \( 2.3 \) in front)
- \( 2.3 \times 10^{-12} \) (exponent = -12)
Now, we can put them in order from largest to smallest:
- \( 2.3 \times 10^{-8} \)
- \( 3.2 \times 10^{-10} \)
- \( 2.3 \times 10^{-10} \)
- \( 2.3 \times 10^{-12} \)
So, the descending order is:
\( 2.3 \times 10^{-8}, 3.2 \times 10^{-10}, 2.3 \times 10^{-10}, 2.3 \times 10^{-12} \).