Problem 46 - Chemistry The Molecular Science

Question

Americium- 240 is made by reacting plutonium- 239 atoms with \(\alpha\) particles. In addition to \({ }^{240} \mathrm{Am},\) the products are a proton and two neutrons. Write a balanced equation for this process.

Step-by-Step Solution

Answer

The balanced equation is \(^{239}_{94}Pu + ^{4}_{2}He \rightarrow ^{240}_{95}Am + ^{1}_{1}H + 2 imes ^{1}_{0}n \).

Step 1: Understanding the Reaction

First, identify the reactants and products involved in the reaction. Americium-240 is produced by reacting Plutonium-239 with alpha particles. The products are Americium-240, a proton (hydrogen nucleus), and two neutrons.

Step 2: Identifying the Reactants

Write down the reaction in symbolic terms. Plutonium-239 is represented as \(^{239}_{94}Pu\) and alpha particles are represented as \(^{4}_{2}He\).

Step 3: Writing the Products

Write the nuclear symbols for the identified products. Americium-240 is represented as \(^{240}_{95}Am\). The proton is represented as \(^{1}_{1}H\), and the neutrons are two \(^{1}_{0}n\) particles.

Step 4: Writing the Unbalanced Equation

Combine the reactants and products into an equation.\[^{239}_{94}Pu + ^{4}_{2}He \rightarrow ^{240}_{95}Am + ^{1}_{1}H + 2 imes ^{1}_{0}n\]

Step 5: Balancing the Equation

Ensure that both mass numbers and atomic numbers are balanced on both sides of the equation. Check totalling:- Mass number: \(239 + 4 = 240 + 1 + 2\times1\)- Atomic number: \(94 + 2 = 95 + 1 + 2\times0\)Both sides balance, so the equation is balanced.

Key Concepts

Plutonium-239

Plutonium-239 is an isotope of plutonium, a heavy metal with unique nuclear properties. It is commonly used in nuclear chemistry due to its ability to undergo fission, releasing a tremendous amount of energy. In its symbolic representation, it is denoted as \(^{239}_{94}Pu\). Characteristics of Plutonium-239 include:

• Mass Number: 239
• Atomic Number: 94
• A radioactive nature which makes it useful in various nuclear reactions

Plutonium-239 plays a key role in the formation of Americium-240 when reacted with an alpha particle. It serves as the basis for the transformation of elements in the nuclear reaction process that forms part of nuclear energy generation.

Alpha Particle Reaction

Alpha particles, symbolized as \(^{4}_{2}He\), consist of two protons and two neutrons, making them similar to the helium nucleus. These particles are crucial in nuclear reactions because they can instigate changes in the targeted isotope when they collide with an atom like Plutonium-239.Key features of alpha particles:

• Mass Number: 4
• Atomic Number: 2
• Positive charge due to protons

Their involvement in nuclear reactions often leads to transmutation, a process where one element is transformed into another. For instance, when an alpha particle combines with Plutonium-239, new elements such as Americium-240 are formed, demonstrating the dynamic nature of nuclear chemistry.

Neutron Emission

In nuclear reactions, neutron emission often occurs as part of the decay or fission process. Neutrons, symbolized as \(^{1}_{0}n\), have a mass number of 1 and no charge, which makes them neutral particles.Important points about neutron emission:

• Mass Number: 1
• Atomic Number: 0 (neutral charge)
• Emitted during certain nuclear processes, essential for balancing nuclear equations

In the given reaction, after the collision of Plutonium-239 with an alpha particle, two neutrons are emitted. This is a common occurrence in nuclear chemistry, assisting in the stabilization of the newly formed nucleus and playing a vital role in balancing nuclear equations.

Nuclear Chemistry Equations

A balanced nuclear chemistry equation ensures that the total mass number and atomic number are equal on both sides of the equation. This reflects the conservation of mass and charge, fundamental principles in nuclear reactions.Steps to balance nuclear equations:

• Identify reactants and products
• Write their nuclear symbols
• Ensure total mass and atomic numbers are the same on each side of the equation

In the example provided, the nuclear equation for the reaction of Plutonium-239 with alpha particles is correctly balanced.\[^{239}_{94}Pu + ^{4}_{2}He \rightarrow ^{240}_{95}Am + ^{1}_{1}H + 2 \times ^{1}_{0}n\]This balance is verified by counting each isotopic species to ensure both sides match in terms of their mass and atomic numbers, following the principles of nuclear chemistry.