Who discovered the meson?

By which law is the energy produced in a nuclear reaction given?

In the Thorium series,$_{90}Th^{232}$ loses a total of $6$ $\alpha$-particles and $4$ $\beta$-particles in ten stages. The final isotope produced in the series is

$_{92}U^{238}$ emits $8$ $\alpha$-particles and $6$ $\beta$-particles. The neutron/proton ratio in the product nucleus is

Radioactive disintegration differs from a chemical change in being

Calculate the mass defect in the following nuclear reaction:
$_1H^2 + _1H^3 \to _2He^4 + _0n^1$
(Given: mass of $_1H^2 = 2.014 \ amu$,$_1H^3 = 3.016 \ amu$,$_2He^4 = 4.004 \ amu$,$_0n^1 = 1.008 \ amu$) (in $amu$)