Answered

What is the nuclear binding energy of an atom that has a mass defect of [tex][tex]$5.0446 \times 10^{-29} kg$[/tex][/tex]? Use [tex][tex]$E=mc^2$[/tex][/tex]. (The speed of light is approximately [tex][tex]$3.00 \times 10^8 m/s$[/tex][/tex].)

A. [tex][tex]$5.61 \times 10^{-46} J$[/tex][/tex]
B. [tex][tex]$1.51 \times 10^{-20} J$[/tex][/tex]
C. [tex][tex]$4.54 \times 10^{-12} J$[/tex][/tex]
D. [tex][tex]$1.78 \times 10^{45} J$[/tex][/tex]



Answer :

To find the nuclear binding energy of an atom given its mass defect, we use Einstein's famous equation [tex]\(E = mc^2\)[/tex], where [tex]\(E\)[/tex] is the energy, [tex]\(m\)[/tex] is the mass defect, and [tex]\(c\)[/tex] is the speed of light in a vacuum.

Here's a step-by-step solution:

1. Identify the given data:
- Mass defect ([tex]\(m\)[/tex]) = [tex]\(5.0446 \times 10^{-29}\, \text{kg}\)[/tex]
- Speed of light ([tex]\(c\)[/tex]) = [tex]\(3.00 \times 10^8\, \text{m/s}\)[/tex]

2. Write down the equation:
[tex]\[ E = mc^2 \][/tex]

3. Substitute the values into the equation:
- Mass defect ([tex]\(m\)[/tex]) is [tex]\(5.0446 \times 10^{-29}\, \text{kg}\)[/tex]
- Speed of light ([tex]\(c\)[/tex]) is [tex]\(3.00 \times 10^8\, \text{m/s}\)[/tex]

Thus, we get:
[tex]\[ E = (5.0446 \times 10^{-29}\, \text{kg}) \times (3.00 \times 10^8\, \text{m/s})^2 \][/tex]

4. Calculate the value:
- First, square the speed of light:
[tex]\[ (3.00 \times 10^8\, \text{m/s})^2 = 9.00 \times 10^{16}\, \text{m}^2/\text{s}^2 \][/tex]
- Then, multiply it by the mass defect:
[tex]\[ E = (5.0446 \times 10^{-29}\, \text{kg}) \times (9.00 \times 10^{16}\, \text{m}^2/\text{s}^2) \][/tex]
- Perform the multiplication:
[tex]\[ E = 4.540140 \times 10^{-12}\, \text{J} \][/tex]

5. Analyze the results:
The energy calculated is [tex]\(4.540140 \times 10^{-12}\, \text{J}\)[/tex].

6. Choose the correct answer:
Among the given options, the value that matches our calculated energy is:
[tex]\[ 4.54 \times 10^{-12}\, \text{J} \][/tex]

Therefore, the nuclear binding energy of the atom is [tex]\(\boxed{4.54 \times 10^{-12}\, \text{J}}\)[/tex].