Question

238,2U --> 234Th +
90

Answer 1

Answer:

$\\_{2}^{4} \alpha$

Explanation:

In this question, we wish to find the missing nuclei for the equation:

$\\_{92}^{238} U\rightarrow _{90}^{234} Th + _{Z}^{A} X$

In order to find the missing species, we need to use the charge and mass balance law. That is, the mass should be conserved: the total mass on the left-hand side with respect to the arrow should be equal to the total mass on the right-hand side with respect to the arrow:

$238 = 234 + A$

Notice from here that:

$A = 238 - 234 = 4$

So far we know that the mass of X is 4. Similarly, we apply the law of charge conservation. The total charge should be conserved:

$92=90+Z$

From here:

$Z = 92-90=2$

We have a particle:

$\\_{2}^{4} X$

Looking at the periodic table, an atom with Z = 2 corresponds to helium. This can also be written as an alpha particle:

$\\_{2}^{4} \alpha$