Question

In another fission reaction, uranium- 235 bombarded with a neutron produces strontium-94, another small nucleus, and three neutrons. Write the complete equation for the fission reaction.

Short answer

The complete equation for the fission reaction is:

Step-by-step solution

Identify the fission reactants

The given fission reaction starts with uranium-235 being bombarded with a neutron. This can be written as:

Write the general reaction equation

The complete fission reaction equation involves the splitting of uranium-235 with a neutron, which results in strontium-94, another nucleus, and three neutrons.

Conserve the atomic number

Make sure the sum of the atomic numbers on both sides of the reaction is balanced. Uranium has an atomic number of 92, and a neutron is neutral with an atomic number of 0. Therefore, the left side has an atomic number of 92.Strontium has an atomic number of 38. Let the atomic number of the unknown small nucleus (X) be denoted as A. The remaining three neutrons contribute zero atomic number as well. Thus, we have:

Write the equation for atomic number conservation

Simplifying this, we get:

Conserve the mass number

Next, we conserve the mass number. The mass number of uranium-235 is 235, and a neutron has a mass number of 1. So, the sum on the left is 236. The mass number of strontium-94 is 94. Let the mass number of the unknown small nucleus (X) be denoted as B. The remaining three neutrons contribute a mass number as well, as each neutron has a mass number of 1.

Write the equation for mass number conservation

Simplifying this, we get:

Solve for atomic number and mass number of the unknown nucleus

Therefore, the unknown nucleus has the atomic number ( A ) and mass number ( B )

Write the complete nuclear equation

Using the determined atomic and mass numbers, the complete balanced fission reaction equation is:

Key concepts

uranium-235 fission

Nuclear fission happens when a heavy nucleus splits into smaller parts. In this case, we are looking at the fission of uranium-235. When uranium-235 absorbs a neutron, it becomes unstable. It then splits into two smaller nuclei, like strontium-94, and other particles. This reaction also releases energy, which makes nuclear fission useful for generating power. Understanding each part that uranium-235 breaks into is key to writing complete equations for these reactions.

atomic number conservation

In any nuclear reaction, the total atomic number must stay the same. The atomic number is the number of protons in a nucleus. For uranium-235, the atomic number is 92. When uranium-235 absorbs a neutron (which has an atomic number of 0), the total atomic number is still 92. After splitting, the sum of all atomic numbers of the products must be equal to 92. So, if one of the products is strontium-94 with an atomic number of 38, the atomic number of the other product must be calculated to ensure the total remains 92.

mass number conservation

Just like with atomic numbers, the total mass number must also be conserved. The mass number is the total number of protons and neutrons in a nucleus. For uranium-235, the mass number is 235. When it absorbs a neutron with a mass number of 1, the total mass number becomes 236. After splitting, the sum of the mass numbers of all resulting nuclei and any extra neutrons must be 236. So, if one product is strontium-94 and three neutrons are released, you must calculate the mass number of the other resulting nucleus to ensure the total mass number is 236.

neutron bombardment

Neutron bombardment is the process of hitting a nucleus with neutrons to start a nuclear reaction. In this case, a neutron hits uranium-235, causing it to split. Neutrons are neutral particles, with no charge, so they don't repel any parts of the nucleus. This makes them very effective at initiating fission. After the reaction, more neutrons are often released, which can then start more fission reactions. This is how a chain reaction happens in nuclear reactors, generating large amounts of energy. Understanding neutron bombardment helps clarify why and how nuclear fission is initiated.