WAEC - Chemistry (2008 - No. 5)
Atom \(^{234} _{88} Q\) decay by alpha emission to give an atom R. The atomic number and mass number of atom R are respectively
86 and 230
87 and 234
88 and 233
90 and 238
Paskaidrojums
\(^{234} _{88} Q \to R + ^4 _2 He\)
\(\therefore R = ^{234 - 4} _{88 - 2} R\)
= \(^{230} _{86} R\)