Question

what is the missing particle?
?→82/36kr+0/-1e
82/35kr
82/35br
82/36kr

Explanation:

Step1: Calculate the mass number

In a nuclear reaction, the mass number is conserved. The mass number of \(_{36}^{82}\text{Kr}\) is \(82\), and the mass number of \(_{-1}^{0}\text{e}\) is \(0\). So the mass number of the missing particle is \(82 + 0=82\).

Step2: Calculate the atomic number

The atomic number is also conserved. The atomic number of \(_{36}^{82}\text{Kr}\) is \(36\), and the atomic number of \(_{-1}^{0}\text{e}\) is \(- 1\). Let the atomic number of the missing particle be \(Z\), then \(Z=36+( - 1)=35\).

Step3: Determine the element

The element with atomic number \(35\) is bromine (\(\text{Br}\)).

Answer:

\(_{35}^{82}\text{Br}\) (the second option \(_{35}^{82}\text{Br}\) in the given choices)