(a(i))[2]
The charge on an electron is $-1.6 \times 10^{-19}\,\text{C}$. The charge on the ion is $+3.2 \times 10^{-19}\,\text{C}$. Deduce, using the ion’s charge, the number of protons in its nucleus. Show your working.
(a(ii))[1]
Write down, in nuclide notation, the symbol representing the nucleus of this charged atom.
(b)[2]
The isotope in Fig. 5.1 is the only stable isotope of beryllium. Explain the meaning of ‘isotope’.
(c)[2]
Explain what keeps electrons in an atom from escaping.