Answer:
a metal and a nonmetal element
Explanation:
The volume of the drum after chilled quickly is 3.6 L.
<u>Explanation:</u>
As per the Charles Law, for any gas at constant pressure, volume of the gas is in direct proportion with the temperature measured in Kelvin. As the temperature increases, the gas expands and vice versa.

After chilling the drum, the volume will get reduced and it can be found as,
V2 =
= 
= 3.6 L
Here the drum is chilled quickly, that is temperature is reduced and so the volume also decreases.
The rate<span> of a </span>reaction increases<span> if the temperature is increased, the concentration of a dissolved reactant is increased and the pressure of a </span>reacting<span> gas is increased. Hope this answers the question. Have a nice day. Feel free to ask more questions.</span>