Older MCQs might not have the typical A, B, C,
D
choices. They
have choices 1, 2, 3, and a combination of them is the answer. Below is the key that maps such
combinations to the answer.
A
1, 2 and 3 are correct
B
1 and 2 only are correct
C
2 and 3 only are correct
D
1 only is correct
Describe the transition elements as metals that: (a) have high densities (b) have high melting points (c) have variable oxidation numbers (d) form coloured compounds (e) often act as catalysts as elements and in compounds
State that a catalyst increases the rate of a reaction, decreases the activation energy, E_a, of a reaction and is unchanged at the end of a reaction
Describe the uses of metals in terms of their physical properties, including: (a) aluminium in the manufacture of aircraft because of its low density (b) aluminium in the manufacture of overhead electrical cables because of its low density and good electrical conductivity (c) aluminium in food containers because of its resistance to corrosion (d) copper in electrical wiring because of its good electrical conductivity and ductility
