The final volume of the balloon is 84.75 ml
calculation
The volume is calculated using Charles law formula
that is V1/T1= V2/T2 where,
V1= 5.00 x10^2 ml
T1= 22.0 °c into kelvin = 22 + 273 = 295 K
V2= ? ml
T2 =0.500 x 10^2 K
make V2 the subject of the formula by multiplying both side by T2
V2 is therefore = T2V1/T1
V2 = (0.500 x 10^2 K x 5.00 x10^2 ml) / 295 K = 84.75 ml