6 This question is about metals
Table 3 shows information about four substances
Table 3
6-1 Which substance could be a metal? [1 mark]
ANSWER
C
6-2 Explain why alloys are harder than pure metals. [3 marks]
ANSWER
In alloy, the atoms are of different sizes so the layers of atoms in an alloy are distorted; so in an alloy, the layers slide over each other less easily than in a pure metal.
6-3 A student wants to compare the reactivity of an unknown metal, Q, with that of zinc. Both metals are more reactive than silver.
The student is provided with:
silver nitrate solution
metal Q powder
zinc powder
a thermometer
Normal laboratory equipment.
No other chemicals are available.
Describe a method the student could use to compare the reactivity of metal Q with that of zinc.
Your method should give valid results. [4 marks]
ANSWER
Measure temperature changes when each metal is added to silver nitrate solution.
Control Variable:
same concentration / volume of solution
same mass / moles of metal
Result: The greater the temperature change the more reactive the metal is.
