91Ó°ÊÓ

What is the cosmic importance of unstable${}^{\mathbf{\text{8}}}\mathbf{\text{Be}}$?

The reaction that will probably power the first commercial fusion reactor is

${}_{\mathbf{\text{1}}}{}^{\mathbf{\text{3}}}{\mathbf{\text{H +}}}_{\mathbf{\text{1}}}^{\mathbf{\text{2}}}\mathbf{\text{H}}{\mathbf{→}}_{\mathbf{\text{2}}}^{\mathbf{\text{4}}}{\mathbf{\text{He +}}}_{\mathbf{\text{0}}}^{\mathbf{\text{1}}}\mathbf{\text{n}}$

How much energy would be produced per mole of reaction?

(Masses of atoms: ${}_{\mathbf{\text{1}}}{}^{\mathbf{\text{3}}}\mathbf{\text{H = 3.01605amu;}}_{\mathbf{\text{1}}}^{\mathbf{\text{2}}}\mathbf{\text{H = 2.0140amu}}$;

${}_{\mathbf{\text{2}}}{}^{\mathbf{\text{4}}}\mathbf{\text{He = 4.00260amu;mass of}}_{\mathbf{\text{0}}}^{\mathbf{\text{1}}}\mathbf{\text{n = 1.008665amu}}$.)

Why might it be difficult to use only a nuclide's$\mathit{N}\mathbf{/}\mathit{Z}$ratio to predict whether it will decay by${\mathit{β}}^{\mathbf{+}}$emission or by${\mathbf{\text{e}}}^{\mathbf{−}}$capture? What another factor is important?

Write balanced nuclear equations for the following:

(a) Alpha decay of${}_{\mathbf{92}}^{\mathbf{234}}\mathbf{\text{U}}$

(b) Electron capture by neptunium-232

(c) Positron emission by${}_{\mathbf{7}}^{\mathbf{12}}\mathbf{}\mathbf{\text{N}}$

Write balanced nuclear equations for the following:

(a)${\mathbf{\text{β}}}^{\mathbf{\text{-}}}$decay of sodium-$\mathbf{26}$

(b)${\mathbf{\text{β}}}^{\mathbf{\text{-}}}$decay of francium- 223

(c) Alpha decay of${}_{\mathbf{83}}^{\mathbf{212}}\mathbf{\text{Bi}}$