Q2.
(a) is a neutral atom of thorium. How many protons, neutrons and electrons does it contain? 90 protons 232 – 90 = 142 neutrons 90 electrons (two correct for 1 mark - all correct for two)
(a) is a neutral atom of thorium. How many protons, neutrons and electrons does it contain?
90 protons
232 – 90 = 142 neutrons
90 electrons
(two correct for 1 mark - all correct for two)
(2 marks)
(b) is a neutral atom of a different isotope of thorium which contains Z electrons. Give possible values for X, Y and Z. X = 90 Y = (any value between) 212 and 252 Z = 90
(b) is a neutral atom of a different isotope of thorium which contains Z electrons. Give possible values for X, Y and Z.
(3 marks) (Total 5 marks)