Calculate the amount of energy released during the `alpha`-decay of
`._(92)^(238)Urarr_(90)^(234)Th+._(2)^(4)He`
Given: atomic mass of `._(92)^(238)U=238.05079 u`, atomic mass of `._(90)^(234)Th=234.04363 u`,
atomic mass `._(2)^(4)He=4.00260u , 1u=931.5 MeV//c^(2)`. Is this decay spontaneous?Give reason.