Band of Stability: Beta Decay: Videos & Practice Problems

Beta decay is a nuclear process that isotopes undergo to achieve stability when they have an excess of neutrons. Isotopes located to the left of the band of stability on the nuclear chart are prone to beta decay, which allows them to convert these extra neutrons into protons. This transformation results in a decrease in the neutron count and an increase in the proton count, shifting the isotope towards the band of stability. An example of this process is the transformation of palladium-107 into silver-107 through the emission of a beta particle. This decay helps isotopes achieve a more stable configuration by balancing their neutron-to-proton ratio.

Band of Stability: Beta Decay

Beta decay is a crucial process that occurs in isotopes located to the left of the band of stability, which is represented by a green curve on a stability graph. Isotopes in this region, such as palladium-107, undergo beta decay to transform into more stable forms, like silver-107. This transformation involves the emission of a beta particle, which is a high-energy electron.

In beta decay, isotopes with an excess of neutrons convert some of these neutrons into protons. This process effectively reduces the neutron count while increasing the proton count, allowing the isotope to move rightward on the stability graph and fall within the band of stability. The primary goal of beta decay is to achieve a more stable nuclear configuration by balancing the ratio of neutrons to protons.

To summarize, beta decay is essential for isotopes with too many neutrons, enabling them to stabilize by increasing their proton count and decreasing their neutron count, thus achieving a more favorable position within the band of stability.

Band of Stability: Beta Decay Example

In the process of beta decay, a nuclide transforms into a different element by emitting a beta particle, which is essentially an electron. For magnesium-28, which has a mass number of 28 and an atomic number of 12, the decay process involves the conversion of a neutron into a proton, resulting in an increase in the atomic number by one while keeping the mass number unchanged.

To analyze this, we start with magnesium-28:

Magnesium-28: ₁₂Mg²⁸

During beta decay, the equation can be represented as follows:

₁₂Mg²⁸ → ₁₃X²⁸ + ^-1e⁰

Here, the mass number remains 28 on both sides of the equation, as the emitted electron does not contribute to the mass. However, the atomic number increases from 12 to 13, indicating that the new element is aluminum. Therefore, the daughter nuclide produced from the beta decay of magnesium-28 is aluminum-28:

Aluminum-28: ₁₃Al²⁸

In conclusion, the beta decay of magnesium-28 results in the formation of aluminum-28, confirming that the correct answer is option D.

How many beta decays would it take to transform tungsten-184 into iridium-184?
a) 5                                         
b) 1                                          
c) 3                                               
d) 4

• A. 5
• B. 1
• C. 3
• D. 4

Answer: (C)

Here’s what students ask on this topic:

What is beta decay and how does it relate to the band of stability?

Beta decay is a nuclear process where an unstable isotope with an excess of neutrons converts a neutron into a proton, emitting a beta particle (an electron) in the process. This transformation helps the isotope move towards a more stable configuration by decreasing the neutron count and increasing the proton count. Isotopes that are located to the left of the band of stability on the nuclear chart are prone to beta decay. The band of stability represents the region where isotopes have a balanced neutron-to-proton ratio, making them stable. Beta decay helps isotopes achieve this balance and fall within the band of stability.

Why do isotopes undergo beta decay?

Isotopes undergo beta decay to achieve a more stable configuration. When an isotope has an excess of neutrons, it is located to the left of the band of stability on the nuclear chart. To move towards stability, the isotope converts one of its neutrons into a proton through beta decay, emitting a beta particle (an electron) in the process. This conversion decreases the neutron count and increases the proton count, helping the isotope achieve a balanced neutron-to-proton ratio and fall within the band of stability.

What happens to the neutron-to-proton ratio during beta decay?

During beta decay, the neutron-to-proton ratio decreases. This is because a neutron in the nucleus is converted into a proton, emitting a beta particle (an electron) in the process. As a result, the number of neutrons decreases by one, and the number of protons increases by one. This shift helps the isotope move towards a more stable configuration by balancing its neutron-to-proton ratio, allowing it to fall within the band of stability.

Can you provide an example of an isotope undergoing beta decay?

An example of an isotope undergoing beta decay is palladium-107 (Pd-107). Palladium-107 has an excess of neutrons and is located to the left of the band of stability. To achieve stability, it undergoes beta decay, where a neutron is converted into a proton, and a beta particle (an electron) is emitted. This process transforms palladium-107 into silver-107 (Ag-107). The neutron count decreases by one, and the proton count increases by one, helping the isotope move towards the band of stability and become more stable.

What is the purpose of the band of stability in nuclear chemistry?

The band of stability in nuclear chemistry represents the region on a nuclear chart where isotopes have a balanced neutron-to-proton ratio, making them stable. It serves as a reference for understanding the stability of different isotopes. Isotopes located within the band of stability have a balanced ratio and are generally stable, while those outside the band are unstable and prone to radioactive decay processes, such as beta decay, to achieve stability. The band of stability helps predict the behavior of isotopes and their tendency to undergo specific decay processes to reach a stable configuration.