Question

what is the missing particle?
233/92 u → 4/2 he + ?
233/90 th
229/90 th
229/92 u

Explanation:

Step1: Calculate the mass number

The mass number of \(^{233}_{92}U\) is \(233\), and the mass number of \(^{4}_{2}He\) is \(4\). Let the mass number of the missing particle be \(A\). According to the conservation of mass number \(A = 233-4=229\).

Step2: Calculate the atomic number

The atomic number of \(^{233}_{92}U\) is \(92\), and the atomic number of \(^{4}_{2}He\) is \(2\). Let the atomic number of the missing particle be \(Z\). According to the conservation of atomic number \(Z=92 - 2=90\).

Step3: Identify the element

The element with atomic number \(90\) is Thorium (\(Th\)).

Answer:

\(^{229}_{90}Th\) (the second option \(^{229}_{90}Th\))