The starting materials in a nuclear change have a total mass of [tex]$2.3465 \times 10^{-27} \, \text{kg}$[/tex]. After the change, the resulting materials have a mass of [tex]$2.3148 \times 10^{-27} \, \text{kg}$[/tex].

How much energy was released during the change?

A. [tex]2.85 \times 10^{-12} \, \text{J}[/tex]
B. [tex]2.08 \times 10^{-10} \, \text{J}[/tex]
C. [tex]2.11 \times 10^{-10} \, \text{J}[/tex]
D. [tex]8.56 \times 10^{-4} \, \text{J}[/tex]



Answer :

To solve this problem, we'll follow these steps:

1. Identify the Initial and Final Masses:
- The initial mass before the nuclear change is [tex]\(2.3465 \times 10^{-27} \, \text{kg}\)[/tex].
- The final mass after the nuclear change is [tex]\(2.3148 \times 10^{-27} \, \text{kg}\)[/tex].

2. Calculate the Mass Defect:
- The mass defect is the difference between the initial and final masses.
[tex]\[ \text{Mass Defect} = \text{Initial Mass} - \text{Final Mass} = 2.3465 \times 10^{-27} \, \text{kg} - 2.3148 \times 10^{-27} \, \text{kg} \][/tex]
- Performing the subtraction gives:
[tex]\[ \text{Mass Defect} = 3.17 \times 10^{-29} \, \text{kg} \][/tex]

3. Calculate the Energy Released Using [tex]\(E=mc^2\)[/tex]:
- The speed of light [tex]\(c\)[/tex] is approximately [tex]\(3 \times 10^8 \, \text{m/s}\)[/tex].
[tex]\[ E = (\text{Mass Defect}) \times (c^2) = 3.17 \times 10^{-29} \, \text{kg} \times (3 \times 10^8 \, \text{m/s})^2 \][/tex]
- Squaring the speed of light:
[tex]\[ (3 \times 10^8 \, \text{m/s})^2 = 9 \times 10^{16} \, \text{m}^2/\text{s}^2 \][/tex]
- Multiplying the mass defect by this value gives:
[tex]\[ E = 3.17 \times 10^{-29} \, \text{kg} \times 9 \times 10^{16} \, \text{m}^2/\text{s}^2 = 2.853 \times 10^{-12} \, \text{J} \][/tex]

Since the closest answer choice to the calculated result [tex]\(2.853 \times 10^{-12} \, \text{J}\)[/tex] is:
[tex]\[2.85 \times 10^{-12} \, \text{J}\][/tex]

Therefore, the energy released during the nuclear change is:
[tex]\[2.85 \times 10^{-12} \, \text{J}\][/tex]