Represent the oxygen atom symbolically along with its two isotopes that have 9 and 10 neutrons.

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.

a basic emergency supply kit could include the following recommended items: water - one gallon of water per person per day for at least three days, for drinking and sanitation. food - at least a three-day supply of non-perishable food. battery-powered or hand crank radio and a noaa weather radio with tone alert.