Answer:
C. 4.00 K
Explanation:
We can solve this using Charles's Law of the ideal gas. The law describes that when the pressure is constant, the volume will be directly proportional to the temperature. Note that the temperature here should only use the Kelvin unit. Before compressed, the volume of the gas is 50ml(V1) and the temperature is 20K (T1). After compressed the volume becomes 10ml(V2). The calculation will be:
V1 / T1= V2 / T2
50ml / 20K = 10ml / T2
T2= 10ml/ 50ml * 20K
T2= 4K