Use the periodic table to complete this equation that represents nuclear fission processes.
${ }_{92}^{235} U+{ }_0^1 n \rightarrow{ }_{56}^{139} Ba+{ }_{B}^{A} C+3{ }_0^1 n$
A: $\square$
B: $\square$
C: $\square$
Answer (1)
Conserve the total mass number: 235 + 1 = 139 + A + 3 ( 1 ) , which gives A = 94 .
Conserve the total atomic number: 92 + 0 = 56 + B + 3 ( 0 ) , which gives B = 36 .
The unknown element C is Krypton (Kr).
Therefore, the answers are A = 94 , B = 36 , and the element is Krypton. A = 94 , B = 36 , C = Kry pt o n
Explanation
Understanding the Problem We are given a nuclear fission reaction equation and need to find the mass number (A) and atomic number (B) of the unknown element C. The equation is: 92 235 U + 0 1 ni g h t ha r p oo n u p 56 139 B a + B A C + 3 0 1 n In nuclear reactions, both the total mass number and the total atomic number must be conserved. This means the sum of the mass numbers on the left side must equal the sum of the mass numbers on the right side, and the same for the atomic numbers.
Conserving Mass Number First, let's conserve the total mass number. The mass number on the left side is 235 + 1 = 236 . On the right side, it is 139 + A + 3 ( 1 ) . So we have: 236 = 139 + A + 3 Now, we solve for A: A = 236 − 139 − 3 = 94
Conserving Atomic Number Next, let's conserve the total atomic number. The atomic number on the left side is 92 + 0 = 92 . On the right side, it is 56 + B + 3 ( 0 ) . So we have: 92 = 56 + B Now, we solve for B: B = 92 − 56 = 36
Identifying the Element Therefore, the unknown element C has a mass number of 94 and an atomic number of 36. Looking at the periodic table, the element with atomic number 36 is Krypton (Kr). So, the unknown element is 36 94 Kr .
Thus, we have: A = 94 B = 36 C = Krypton (Kr)
Examples
Nuclear fission is used in nuclear power plants to generate electricity. The fission of uranium atoms releases a tremendous amount of energy, which heats water to create steam. This steam then turns turbines connected to generators, producing electrical power. Understanding nuclear equations like the one above helps scientists and engineers manage and optimize these processes, ensuring safe and efficient energy production. For example, controlling the number of neutrons released is crucial for maintaining a stable chain reaction.
