Question

identify the missing daughter in the following nuclear reaction:
4219k→______+0-1e
4220ca
4119k
4220ca
4218ar

Explanation:

Step1: Apply conservation of atomic number

The atomic number of \(K\) is \(19\), and for the electron (\(_{-1}^0e\)) the atomic number is \(- 1\). Let the atomic number of the daughter nucleus be \(Z\). Then \(19=Z+( - 1)\), so \(Z = 20\).

Step2: Apply conservation of mass number

The mass number of \(K\) is \(42\), and for the electron (\(_{-1}^0e\)) the mass number is \(0\). Let the mass number of the daughter nucleus be \(A\). Then \(42=A + 0\), so \(A=42\).

Step3: Identify the element

The element with atomic number \(Z = 20\) is \(Ca\) (calcium).

Answer:

\(_{20}^{42}Ca\)