Part 1: Download a Specification AS and A level combined specification Part 2: Making Notes Fundamental particles (specification points) Appreciate that knowledge and understanding of atomic structure has evolved over time. Protons, neutrons and electrons: relative charge and relative mass. An atom consists of a nucleus containing protons and neutrons surrounded by electrons Mass number and isotopes (specification point) The principles of a simple time of flight (TOF) mass spectrometer, limited to ionisation, acceleration to give all ions constant kinetic energy, ion drift, ion detection and data analysis. Using the specification points above 1.Write a summary of the key developments in atom structure from the ancient Greeks to the current taught model, including key experiments and diagrams (not electron arrangement). 2.Explain the principles of a simple time of flight (TOF) mass spectrometer, limited to ionisation, acceleration to give all ions constant kinetic energy, ion drift, ion detection and data analysis. Part 3: Exam Style Questions Q1.(a) Describe how ions are formed in a time of flight (TOF) mass spectrometer ……………………………………….(2) (b) A TOF mass spectrometer can be used to determine the relative molecular mass of molecular substances. Explain why it is necessary to ionise molecules when measuring their mass in a TOF mass spectrometer ………………………………………..(2) (Total 4 marks) Chemistry

(ii) Which one of the following is a fundamental particle that would not be deflected by an electric field? Circle correct answer. A electron B neutron C proton (1) (ii) State, in terms of fundamental particles, why the isotopes 10 B and 11 B have similar chemical reactions (1) (Total 3 marks) Chemistry A 3H3H B 4 He C 5 He D 4 Li Q2.Which of these atoms has the smallest number of neutrons? (Total 1 mark) Table 1 Particleprotonneutronelectron Mass / g × 10 – × 10 – × 10 –24 Q3.(a) Table 1 shows some data about fundamental particles in an atom. (i) An atom of hydrogen can be represented as 1 H Use data from Table 1 to calculate the mass of this hydrogen atom (1) Relative massRelative charge Proton Electron Q4. (a) Complete the following table. (2)

Chemistry (b) An atom of element Q contains the same number of neutrons as are found in an atom of 27 Al. An atom of Q also contains 14 protons. (i) Give the number of protons in an atom of 27 Al (2) (ii) Deduce the symbol, including mass number and atomic number, for this atom of element Q (3) (c) Define the term relative atomic mass of an element (2) (Total 7 marks)