Answer:
Alpha decay
Explanation:
Observing the question given, we discovered that the mass number of 240 94 Pu reduced by 4 and the atomic number reduce by 2 in the product obtained from the reaction. This clearly indicates that 240 94 Pu is undergoing alpha decay because atoms that ungoes alpha decay has a decrease of 4 in the mass number and a decrease 2 in the atomic number.
The attached photo gives further explanation...
