_1__Atomic_Structure

MATTER H2 CHEMISTRY / 9729 GCE ADVANCED LEVEL © INTELEAGUE 2018 9729_CH_C1_2018 1 CHAPTER 1 Atomic Structure Learning Outcomes Candidates should be able to: (a) identify and describe protons, neutrons and electrons in terms of their relative charges and relative masses (b) deduce the behaviour of beams of protons, neutrons and electrons in an electric field (c) describe the distribution of mass and charges within an atom (d) deduce the numbers of protons, neutrons and electrons present in both atoms and ions given proton and nucleon numbers (and charge) (e) (i) describe the con tribution of protons and neutrons to atomic nuclei in terms of proton number and nucleon number (ii) distinguish between isotopes on the basis of different numbers of neutrons present (f) describe the number and relative energies of the s, p and d orbitals f or the principal quantum numbers 1, 2 and 3 and also the 4s and 4p orbitals (g) describe the shapes of s, p and d orbitals [knowledge of wave functions is not required] (h) state the electronic configuration of atoms and ions given the proton number (and charge) (i) explain the factors influencing the ionisation energies of elements (see the Data Booklet) (j) deduce the electronic configurations of elements from successive ionisation energy data (k) interpret successive ionisation energy data of an element in terms of the position of that element within the Periodic Table Trends and variations in atomic and physical properties For elements in the third period (sodium to chlorine), and in Group 2 (magnesium to barium) and Group 17 (chlorine to iodine) candidates should be able to: (l) recognise variation in the electronic configurations across a Period and down a Group (m) describe and explain qualitatively the trends and variations in atomic radius, ionic radius, first ionisation energy and electronegativity: (i) across a Period in terms of shielding and nuclear charge (ii) down a Group in terms of increasing number of electronic shells and nuclear charge (n) define the terms relative atomic, isotopic, molecular and formula mass, based on the 12C scale (o) calculate the relative at omic mass of an element given the relative abundances of its isotopes (p) explain what is meant by a transition element, in terms of d block elements forming one or more stable ions with partially filled d subshells (q) state the electronic configuration of a first row transition element and its ions (r) explain why atomic radii and first ionisation energies of the transition elements are relatively invariant

2 PROPERTIES OF THE 3 SUBATOMIC PARTICLES Property Proton Electron Neutron Relative charge +1 –1 0 Relative mass 1 1 1836 1 Atom: The smallest component of an element having the chemical properties of the element Isotopes: Atoms of an element that have the same proton number but different nucleon numbers Proton number: The number of protons in the nucleus of each atom of an elem