Answer:
Curium-247 i.e. ²⁴⁷₉₆Cm
Explanation:
Alpha decay is given by following general equation,
ᵃₓA → ⁴₂He + ᵃ⁻⁴ₓ₋₂B
Where;
A = Parent Isotope
B = Daughter Isotope
ᵃ = Mass Number
ₓ = Atomic Number
Californium-251 is the parent isotope in our case and it has 98 protons (atomic number) and is given as,
²⁵¹₉₈Cf
The alpha decay reaction of Californium-251 will be as,
²⁵¹₉₈Cf → ⁴₂He + ²⁴⁷₉₆B
The symbol for B with atomic number 96 was found to be the atom of Curium (Cm) by inspecting periodic table. Hence, the final equation is as follow,
²⁵¹₉₈Cf → ⁴₂He + ²⁴⁷₉₆Cm
