Use the periodic table to complete this equation that represents nuclear fission processes.

[tex]\[ {}^{235}_{92} U + {}^{1}_{0} n \rightarrow {}^{139}_{56} Ba + {}^{94}_{36} Kr + 3{}^{1}_{0} n \][/tex]

A: [tex]\(\square\)[/tex]

B: [tex]\(\square\)[/tex]

C: [tex]\(\square\)[/tex]



Answer :

The given equation represents a nuclear fission process. To find the missing parts of the equation, we need to ensure conservation of both atomic numbers (protons) and mass numbers (nucleons).

We start with uranium-235 [tex]\(_{92}^{235}U\)[/tex] and a neutron [tex]\(_0^1n\)[/tex] on the left side of the equation:
[tex]\[ _{92}^{235}U + _0^1n \rightarrow_{56}^{139}Ba + \square + 3_0^1n \][/tex]

### Conservation of Mass Number:
The mass number (A) on the left side is 235 (uranium) + 1 (neutron) = 236.

On the right side, we have:
- Barium: [tex]\(_{56}^{139}Ba\)[/tex], which contributes 139.
- 3 neutrons: Each with a mass number of 1, so 3 × 1 = 3.

Let's denote the mass number of the unknown nucleus [tex]\(_Z^AC\)[/tex] as [tex]\(A\)[/tex]. Hence, we have:
[tex]\[ 139 + A + 3 = 236 \][/tex]
Solving for [tex]\(A\)[/tex]:
[tex]\[ A = 236 - 139 - 3 = 94 \][/tex]

### Conservation of Atomic Number:
The atomic number (Z) on the left side is 92 (uranium) + 0 (neutron) = 92.

On the right side:
- Barium: [tex]\(Z = 56\)[/tex]
- The unknown nucleus has an atomic number [tex]\(Z\)[/tex].
- 3 neutrons contribute 0 to the atomic number.

So,
[tex]\[ 56 + Z = 92 \][/tex]
Solving for [tex]\(Z\)[/tex]:
[tex]\[ Z = 92 - 56 = 36 \][/tex]

The element with atomic number 36 is Krypton ([tex]\(_{36}\text{Kr}\)[/tex]).

Therefore, the unknown nucleus is:
[tex]\[ _{36}^{94}Kr \][/tex]

### Complete Equation:
The complete nuclear fission equation is:
[tex]\[ _{92}^{235}U + _0^1n \rightarrow_{56}^{139}Ba + _{36}^{94}Kr + 3_0^1n \][/tex]

By ensuring conservation of both mass number and atomic number, the answer is verified. The spaces can now be filled as follows:
- A: [tex]\(139\)[/tex]
- B: [tex]\(94\)[/tex]
- C: [tex]\(3\)[/tex]

To sum up the result:
[tex]\[ A: \; 139, \quad B: \; 94, \quad C: \; 3 \][/tex]