Answer: 3729.87MeV
Step-by-step explanation:
²³¹₉₁Pa → ²²⁷₈₉Ac + ⁴₂He
Molar mass of of He = 4.0
Number of moles = 1
Na (Avogadro's number) = 6.023*10²³ atoms
Note : 1 mole = molarmass = Avogadro's number
Molar mass = 4.000 * 1 = 4g = 4*10^-3 kg
Mass = (number of moles * molar mass ) / Avogadro's number.
Mass = 4.0*10^-3 / 6.023*10^-23
Mass = 6.64 * 10^-27 kg
from Einstein's theory of relativity, energy E and mass m are interconvertible.
∇E = ∇mc²
E = (6.64*10^-27) * (3.0*10⁸)²
E = 5.98*10^-10J
1eV = 1.602*10-19J
XeV = 5.98*10-19J
X = (5.98*10^-10 * 1) / 1.602*10-19
X = 37328333958eV
X = 3729.87MeV