Question

what is the missing particle?

233/92u→4/2he+?

229/90th
233/90th
229/92u

Explanation:

Step1: Calculate the mass number of the missing particle

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 \(A + 4=233\), so \(A = 233 - 4=229\).

Step2: Calculate the atomic number of the missing particle

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 \(Z+2 = 92\), so \(Z=92 - 2 = 90\).

Step3: Determine the element

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

Answer:

\(^{229}_{90}Th\)