Question

what is the missing particle?

147 62 sm → 4 2 he + ?

143 62 nd

143 60 nd

143 60 sm

Explanation:

Step1: Calculate the mass number of the missing particle

The mass number of \(^{147}_{62}Sm\) is \(147\), 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 \(A + 4=147\), so \(A = 147 - 4=143\).

Step2: Calculate the atomic number of the missing particle

The atomic number of \(^{147}_{62}Sm\) is \(62\), 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 \(Z + 2=62\), so \(Z = 62 - 2 = 60\).

Step3: Determine the element

Looking at the periodic table, the element with atomic number \(60\) is Neodymium (\(Nd\)).

Answer:

\(^{143}_{60}Nd\) (the second option \(^{143}_{60}Nd\))