Question

238,2U --> 234Th +
90

Answer 1

`\\_(2)^(4) \alpha`

Step-by-step 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`