The area of particle 1 is 2.5 mm^2 and the area of particle 2 is 0.5 mm^2. To find how many times bigger the area of particle 1 is compared to the area of particle 2, we can divide the area of particle 1 by the area of particle 2:

Area of particle 1 / Area of particle 2 = (2.5 mm^2) / (0.5 mm^2) = 5

Therefore, the area of particle 1 is 5 times bigger than the area of particle 2.