Question

What particle is produced during the following decay processes: \((\mathbf{a})\) sodium-24 decays to magnesium-24; \((\mathbf{b})\) mercury-188 decays to gold-188; \((\mathbf{c})\)iodine-122 decays to xenon-122; \((\mathbf{d})\) plutonium-242 decays to uranium-238?

Short answer

In the given decay processes: \((\mathbf{a})\) sodium-24 to magnesium-24 and \((\mathbf{b})\) mercury-188 to gold-188, both produce an electron \(\beta^{-}\) (a beta-minus particle) since they are beta decays. \((\mathbf{c})\) iodine-122 to xenon-122 produces a positron \(\beta^{+}\) (a beta-plus particle) due to positron emission. And finally, \((\mathbf{d})\) plutonium-242 to uranium-238 produces an alpha particle (_2^4He) as it is an alpha decay process.

Step-by-step solution

Identify the decay process in each case

In order to identify the particles produced, we need to first identify the decay process occurring in each case. \((\mathbf{a})\) Sodium-24 decays to magnesium-24: This is a beta decay process, as the atomic number (number of protons) increases by 1 while the atomic mass (number of protons and neutrons) remains the same. \((\mathbf{b})\) Mercury-188 decays to gold-188: This is also a beta decay process, as the atomic number increases by 1, and the atomic mass remains the same. \((\mathbf{c})\) Iodine-122 decays to xenon-122: In this decay process, the atomic number decreases by 1 while the atomic mass remains the same. This is a positron emission process (beta-plus decay). \((\mathbf{d})\) Plutonium-242 decays to uranium-238: This decay process involves the atomic number decreasing by 2, and the atomic mass decreasing by 4. This indicates an alpha decay process. Now that the decay processes are identified, we can determine the particles produced during each decay.

Identify the particle produced in each decay process

Based on the type of decay identified in Step 1, we can now identify the particle produced in each decay process. \((\mathbf{a})\) Sodium-24 decays to magnesium-24: Beta decay produces an electron \(\beta^{-}\) (a beta-minus particle). \((\mathbf{b})\) Mercury-188 decays to gold-188: Beta decay produces an electron \(\beta^{-}\) (a beta-minus particle). \((\mathbf{c})\) Iodine-122 decays to xenon-122: Positron emission produces a positron \(\beta^{+}\) (a beta-plus particle). \((\mathbf{d})\) Plutonium-242 decays to uranium-238: Alpha decay produces an alpha particle, which consists of 2 protons and 2 neutrons, represented by \(_2^4\text{He}\). And there we have it! We've identified the particle produced during each decay process: an electron (\(\beta^{-}\)) for \((\mathbf{a})\) and \((\mathbf{b})\), a positron (\(\beta^{+}\)) for \((\mathbf{c})\), and an alpha particle for \((\mathbf{d})\).

Key concepts

Beta Decay

Beta decay is a fascinating process of nuclear decay where an unstable atom transforms into a more stable one by changing a neutron into a proton. When this happens, it emits a particle called a beta particle. A beta particle is essentially a high-energy electron, denoted by - Beta-minus decay starts with a neutron which splits into a proton, an electron (the beta particle), and an anti-neutrino. The atom's atomic number increases by one, but its mass number stays the same because only the inside of a neutron has transformed. For example, in the decay of sodium-24 to magnesium-24, a beta-minus particle is emitted. Sodium has 11 protons, and after gamma decay, it has 12, turning it into magnesium.

Positron Emission

Positron emission is another type of beta decay known as beta-plus decay. In this process, a proton inside an unstable nucleus changes into a neutron. During this transformation, the nucleus emits a positron and a neutrino. - A positron is the antimatter counterpart of an electron, symbolized as In positron emission, the mass number remains unchanged, but the atomic number decreases by one since a proton has converted to a neutron. An example of this process is iodine-122 decaying to xenon-122. Here, a positron is released as iodine sheds a proton to stabilize into xenon.

Alpha Decay

Alpha decay is a type of nuclear decay where an unstable nucleus releases an alpha particle to become more stable. An alpha particle consists of two protons and two neutrons, making it equivalent to a helium nucleus, - This process significantly changes the identity of the element. The atomic number decreases by two, and the mass number decreases by four, as the nucleus ejects a piece of itself. In the example of plutonium-242 decaying to uranium-238, an alpha particle is emitted. The original atom loses two protons and becomes a new element, uranium.

Nuclear Reactions

Nuclear reactions are powerful processes where the nuclei of atoms undergo change. These reactions can lead to the transformation of elements and the release of vast amounts of energy. - There are two main types of nuclear reactions: fission and fusion. Fission splits heavy atomic nuclei into smaller pieces, often releasing neutrons as well, while fusion merges smaller nuclei into a larger nucleus. In addition to these, other reactions involve the absorption or emission of particles like neutrons, electrons, positrons, and alpha particles. The specific transformations involve intricate changes in the nuclear structure of atoms, often leading to the generation of new elements.