A neutral atom of beryllium-9 (49Be^{9}_{4}\text{Be}49Be) consists of a nucleus containing protons and neutrons, with electrons in outer orbits. Identify the names of: (i) the negative subatomic particles in the outer orbits, and (ii) the uncharged subatomic particles in the nucleus.
An atom of sodium has the nuclide notation:
1123Na ^{23}_{11}\text{Na} 1123NaState the number of protons, neutrons, and electrons in this neutral atom.
A radioactive isotope of sodium (1124Na^{24}_{11}\text{Na}1124Na) has a half-life of 15 hours. A sample contains 320 mg of this isotope. Calculate the time taken for this isotope to decay to 10 mg.
284 exam-style questions on CIE IGCSE Physics 5.1 The nuclear model of the atom, covering 5.1.1a Structure of the atom and ions, 5.1.1b Alpha-particle scattering, 5.1.2a Composition of the nucleus and isotopes, 5.1.2b Proton number, nucleon number and nuclide notation, and 5.1.2c Nuclear fission and nuclear fusion. Each one has a worked solution and a mark scheme showing where the marks go.