International Baccalaureate IB Chemistry
3.1.1 Periods, groups and blocks
Identify the positions of metals, metalloids and non‑metals in the periodic table. The four blocks associated with the sublevels s, p, d, f should be recognised.
3.1.2 Period number and valence electrons
Deduce the electron configuration of an atom up to $Z = 36$ from the element’s position in the periodic table and vice versa. Groups are numbered from 1 to 18. The classifications “alkali metals”, “halogens”, “transition elements” and “noble gases” should be known.
3.1.3 Periodicity of element properties
Explain the periodicity of atomic radius, ionic radius, ionisation energy, electron affinity and electronegativity.
3.1.4 Group 1 & 17 Reactivity Trends
Trends down a group (metallic/non‑metallic character) Describe and explain the reactions of group 1 metals with water, and of group 17 elements with halide ions.
3.1.5 Continuum of oxide properties
Deduce equations for the reactions with water of the oxides of group 1 and group 2 metals, carbon and sulfur.
3.1.6 Oxidation state concept
Deduce the oxidation states of an atom in an ion or a compound.
3.1.7 Discontinuities in ionisation energy trend
Discontinuities occur in the trend of increasing first ionisation energy across a period. Explain how these discontinuities provide evidence for the existence of energy sublevels. Explanations should be based on the energy of the electron removed, rather than on the “special stability” of filled and half‑filled sublevels.
3.1.8 Properties of transition elements
Transition elements have incomplete d‑sublevels that give them characteristic properties. Recognise properties, including: variable oxidation state, high melting points, magnetic properties, catalytic properties, formation of coloured compounds and formation of complex ions with ligands.
3.1.9 First‑Row Transition Ions
Variable oxidation states of transition elements The formation of variable oxidation states in transition elements can be explained by the fact that their successive ionisation energies are close in value. Deduce the electron configurations of ions of the first‑row transition elements.
3.1.10 Colour of transition‑element complexes
Transition element complexes are coloured due to the absorption of light when an electron is promoted between the orbitals in the split d‑sublevels. The colour absorbed is complementary to the colour observed. Apply the colour wheel to deduce the wavelengths and frequencies of light absorbed and/or observed.