In this activity you will use the virtual lab to determine the concentration of a strong monoprotic acid. To do this, you can perform a titration using NaOH and phenolphthalein found in the virtual lab. (Note: The concentration of the acid is between 0.025M and 2.5M so you will need to dilute the NaOH solution so that the volume to reach the endpoint is between 10 and 50 mL).

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.