Which of the following substances would best be measured using mole quantities?

Question 2 options:

people in the world

coin money in circulation

molecules of water in the ocean

hairs on a shaggy dog

indium, and thallium have three electrons i think

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.