Elements of Life - Learning outcomes

Candidates should be able to:

(a) describe protons, neutrons and electrons in terms of their mass and relative charge;

(b) Describe the structure of atoms in terms of protons, neutrons and electrons;

(c) explain and use the terms: atomic number, mass number, isotope, Avogadro constant, relative isotopic mass, relative atomic mass, relative formula mass, relative molecular mass;

(d) describe the elementary principles underlying the operation of a mass spectrometer;

(e) use data from a mass spectrometer to determine relative atomic mass and the relative abundance of isotopes;

(f) use the concept of amount of substance to perform calculations involving: masses of

substances, empirical and molecular formulae, percentage composition; N3.2

(g) outline the formation of elements in stars by nuclear fusion processes;

(h) explain the occurrence of absorption and emission atomic spectra;

(i) interpret the atomic emission spectrum of hydrogen in terms of changes in electronic energy levels;

(j) recall that the nuclei of some atoms are unstable, and that these atoms are radioactive;

(k) recall the different properties of alpha, beta and gamma radiations;

(l) use nuclear symbols to write equations for nuclear processes, both fusion and radioactive decay;

(m) explain the use of radioactive tracers;

(n) recall that the Periodic Table lists elements in order of atomic (proton) number and groups elements together according to their common properties;

(o) understand the way that ideas behind the Periodic Table developed historically;

(p) relate the position of an element in the Periodic Table to its electron structure (in terms of electron shells) and vice versa;

(q) interpret periodic trends in the properties of elements, in terms of:

(i) melting point and boiling point,

(ii) electrical conductivity,

(iii) ionisation enthalpy;

(r) relate ease of ion formation to ionisation enthalpy;

(s) write equations for the first and successive ionisation enthalpies of an element;

(t) use given data to describe trends in a group of the Periodic Table and to make predictions concerning the properties of an element in the group;

(u) write and interpret balanced chemical equations;

(v) describe and compare the following properties of the elements Mg, Ca, Sr, Ba in Group 2:

(i) reactions of the elements with water,

(ii) acid-base character of the oxides and hydroxides,

(iii) thermal stability of the carbonates,

(iv) solubilities of hydroxides and carbonates;

(w) use simple electron ‚dot-cross diagrams to describe how atoms bond through ionic, covalent and dative covalent bonds;

(x) describe a simple model of metallic bonding

(y) use the electron pair repulsion principle to predict the shapes of simple molecules (such as CH₄, NH₃ and H₂O) and ions (such as NH ^{4 +}) with up to four outer pairs of electrons (any combination of bonding pairs and lone pairs) (no treatment of hybridisation or molecular orbitals is expected);

(z) explain molecular shape in terms of bond angles.