  1. Isotopes are forms of atoms which have a) The same number of electrons but a different number of protons in the nucleus b) The same number of protons but a different number of neutrons in the nucleus c) The same number of neutrons but a different number of protons in the nucleus d) The same mass number but different atomic numbers 2.
Which of the following scientists produced the model of the atom which is today considered to be the most acceptable. a) Avogadro b) J. J. Thomson c) Ernest Rutherford d) Neils Bohr 3. The definition of an “atomic mass unit” is a) The mass of one atom of hydrogen b) The mass of one proton c) The mass of 6.02 x 1023 atoms of carbon-12 d) 1/12 the mass of a carbon-12 atom 4.
Which of the following statements is incorrect? a) Gamma rays are not affected by magnetic fields. b) Alpha particles are more massive and therefore have a greater penetrating power than beta particles. c) Beta particles are less ionising that alpha particles d) If an electron and a positron collide they can create a gamma ray 5. The half-life of a radio nuclide is a) Half the time taken for all of a sample of the nuclide to decay b) The time taken for a sample of the substance to split in half c) Numerically equal to half the bonding energy of the nuclide d) The time taken for half of a sample of the nuclide to decay 6.
The term “LD50” means a) The dose of nuclear radiation which will kill 50% of the population within 30 days. b) The dose of nuclear radiation which will kill 50% of the population without time restriction c) The dose of nuclear radiation which will kill a person within 50 days d) 50% of the dose of nuclear radiation needed to kill a person 7. Which of the following ionising radiations had the greatest range in air? a) Alpha rays b) Beta rays c) Gamma rays d) Neutrons 8.
The binding energy of a nuclide is a) The quantity of energy needed to separate it from another nuclide b) The energy released when on ‘splits the atom’ c) Is equal to the energy released when a uranium-238 nucleus undergoes fission d) Will be converted to mass if the nuclide is decomposed into its component nucleons 9. The half life of a radio isotope is ten minutes. The probability that a particular nucleus which has survived for ten minutes will decay in the next ten minutes is a) 0% b) 25% c) 50% d) 100% 
