4.2a Variation of properties across a period
Students should be able to show the variation in properties across Period 3 (sodium to
argon) as illustrated by:
(i) reactions of the elements with oxygen, chlorine and water
(ii) the formulae and acid-base character of the oxides and hydroxides of the metals and
oxides of the non-metals
· limited to Na2O,
MgO, Al2O3, NaOH, Mg(OH)2, Al(OH)3, SiO2,
P4O10, SO2, SO3 and Cl2O
(iii) the formulae of the chlorides, and their reactions with water
· the reaction with water limited to
NaCl, MgCl2, AlCl3, SiCl4, PCl3, PCl5,
S2Cl2
(iv) interpret the reactions in (a)(ii) and (a)(iii) in terms of the structure and bonding of the
oxides and chlorides
4.2b Variation of properties down a group
Students should be able to:
(i) recall the reasons for the increase in metallic character with increase in atomic number
in Group 4
· to include the physical properties of the element
· the acid-base character of their oxides, including the equations for their reactions
(excluding tin).
(ii) recall that the +2 oxidation state in Group 4 becomes more stable as the atomic number
increases
· limited to the chemistry of tin and lead
· ‘the inert pair effect’ should not be stated as a reason for this behaviour
(iii) recall and explain the structure of carbon tetrachloride
(iv) recall and explain the behaviour of carbon tetrachloride with water and contrast this
behaviour with that of silicon tetrachloride with water.