Question

Bombarding Li-6 with a neutron produces a radioactive nuclide and an alpha particle. Identify the radionuclide.

Short answer

The radionuclide produced is Tritium ( $^3_1H$ ).

Step-by-step solution

Understand the given reaction

We are given that Lithium-6 (\(^6_3Li\)) is bombarded with a neutron (\(^1_0n\)) and this produces a radioactive nuclide and an alpha particle (\(^4_2He\)). The reaction can be represented as \(^6_3Li + ^1_0n \rightarrow \text{Radionuclide} + ^4_2He\).

Apply conservation of mass and atomic numbers

In nuclear reactions, the sum of mass numbers (top numbers) and atomic numbers (bottom numbers) on both sides of the equation must be equal. Here, the left side of the equation has a total mass number of $6 + 1 = 7$ and atomic number of $3 + 0 = 3$ .

Determine the mass and atomic numbers of the radionuclide

The right side of the equation must also add up to a mass number of 7 and atomic number of 3. The alpha particle $^4_2He$ contributes a mass number of 4 and atomic number of 2. Therefore, the remaining mass number for the radionuclide is $7 - 4 = 3$ , and the atomic number is $3 - 2 = 1$ .

Identify the radionuclide

The element with atomic number 1 is Hydrogen. The radionuclide with mass number 3 is Tritium, represented as $^3_1H$ . Therefore, the reaction produces Tritium as the radionuclide.

Key concepts

Radioactive Nuclides

In the world of nuclear reactions, radioactive nuclides are key players. These are unstable isotopes that release radiation as they decay to become more stable. When certain elements undergo nuclear reactions, they can transform into radioactive nuclides.
In the example from the exercise, bombarding Lithium-6 with a neutron results in the creation of a radioactive nuclide. This process illustrates how elements can alter their identities, producing new materials with different properties.
Radioactive nuclides are important in various applications, including medical imaging, radiation therapy, and nuclear power. Understanding them helps us harness their power safely and effectively.

Conservation of Mass

One of the fundamental principles in nuclear chemistry is the conservation of mass. This principle dictates that the total mass of products in a nuclear reaction must equal the total mass of the reactants.
In our exercise, when Lithium-6 is bombarded with a neutron, the sum of the mass numbers on both sides of the equation needs to remain constant. Specifically, the left-hand side has a combined mass number of 7 (from Lithium-6 and the neutron). Thus, the right-hand side must also sum up to a mass number of 7.
This ensures that the mass is balanced and doesn't just disappear or appear out of nowhere, reflecting the need for careful accounting in nuclear equations. Such calculations are crucial to accurately predicting the new elements formed in reactions.

Atomic Numbers

Alongside the conservation of mass, the conservation of atomic numbers is also crucial. Each element is defined by its atomic number, which tells us the number of protons in the nucleus.
In nuclear reactions, the sum of atomic numbers must be conserved. For the exercise example, Lithium-6 and the neutron together have a total atomic number of 3 (3 for lithium and 0 for the neutron). The products of the reaction need to reflect this same atomic number total.
The balance of atomic numbers helps chemists deduce which new elements or isotopes are created during reactions. By knowing the starting materials, they can determine the identity of newly formed substances.

Tritium

Tritium is a fascinating isotope of hydrogen. It has the symbol \( ^3_1H \) and is known for being radioactive. Unlike the typical form of hydrogen, which includes just one proton, tritium contains one proton and two neutrons in its nucleus, giving it a mass number of 3.
Tritium is produced in nuclear reactions, such as the one in the exercise where Lithium-6 is bombarded by a neutron. The resulting tritium is a key output, illustrating the changing nature of elements under certain conditions.
Though tritium is radioactive, it emits relatively weak radiation, making it useful in various applications. It's utilized in scientific research, illuminated watches, and even in nuclear fusion experiments. Understanding tritium is crucial for harnessing its potential in technology and science.