Write a nuclear equation for the following:
Iodine 131 undergoes beta decay two times
Plutonium 239 is an alpha emitter
Th 234 undergoes beta decay once and then alpha decay
How do I go about writing nuclear equations?
To write nuclear equations, you need to understand the basics of nuclear decay and reactions. Nuclear decay involves the emission of particles from the nucleus of an atom, resulting in the formation of a new element. There are three common types of nuclear decay: alpha decay, beta decay, and gamma decay.
Here's how to write nuclear equations for the given scenarios:
1. Iodine 131 undergoing beta decay two times:
Beta decay involves the emission of a beta particle (an electron) from the nucleus. Since Iodine 131 undergoes beta decay twice, it means two electrons are emitted.
The initial isotope is Iodine 131 (with atomic number 53 and mass number 131). The final product will have an atomic number increased by 2 (since two beta decays occurred), but the mass number will remain the same.
The nuclear equation for Iodine 131 undergoing beta decay two times can be written as:
131 I --> 131 Xe + 2 e-
2. Plutonium 239 being an alpha emitter:
Alpha decay involves the emission of an alpha particle (two protons and two neutrons) from the nucleus. In this case, Plutonium 239 is the initial isotope.
The nuclear equation for Plutonium 239 undergoing alpha decay can be written as:
239 Pu --> 235 U + 4 He
Here, the atomic number decreases by 2 (since two protons are lost), and the mass number decreases by 4, representing the loss of an alpha particle.
3. Thorium 234 undergoing beta decay followed by alpha decay:
Thorium 234 undergoing beta decay means it emits a beta particle (electron) to become a new isotope. After that, the new isotope undergoes alpha decay, emitting an alpha particle, resulting in further change of the element.
Begin by writing the nuclear equation for beta decay of Th 234:
234 Th --> 234 Pa + e-
Then, write the nuclear equation for alpha decay of Pa 234:
234 Pa --> 230 Th + 4 He
Combining both equations, you get the complete nuclear equation for Th 234 undergoing beta decay once and then alpha decay:
234 Th --> 230 Th + 4 He + e-
In summary, understanding the type of decay involved in each scenario and knowing the resultant particles emitted will allow you to write accurate nuclear equations.