To arrange the sets of numbers in descending order, we need to compare their values. Since all numbers are in scientific notation, we first look at the exponents:
- \( 7.2 \times 10^{-30} \)
- \( 7 \times 10^{-30} \)
- \( 7.6 \times 10^{-25} \)
- \( 7.2 \times 10^{-25} \)
Comparing the exponents:
- The larger the exponent in scientific notation, the larger the value of the number. Therefore, since \(10^{-25}\) is greater than \(10^{-30}\), all numbers with an exponent of \(-25\) will be larger than any number with an exponent of \(-30\).
- Among \(7.6 \times 10^{-25}\) and \(7.2 \times 10^{-25}\), \(7.6\) is larger than \(7.2\).
- For the numbers with exponents of \(-30\), \(7.2\) is larger than \(7\).
So, we can summarize this as follows:
- The largest number is \(7.6 \times 10^{-25}\).
- The next is \(7.2 \times 10^{-25}\).
- Then, \(7.2 \times 10^{-30}\).
- Finally, the smallest is \(7 \times 10^{-30}\).
Thus, the correct descending order is:
7.6×10⁻²⁵, 7.2×10⁻²⁵, 7.2×10⁻³⁰, 7×10⁻³⁰.
The second option from your list is the one that shows this order:
7.6×10⁻²⁵, 7.2×10⁻²⁵, 7.2×10⁻³⁰, 7×10⁻³⁰.
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