A piece of sodium metal reacts completely with water according to the reaction:
2Na(s) + 2H2O(l) + 2NaOH(aq) + H2(g)
The hydrogen gas is collected over water at 25°C. The volume
of the gas generated is 246 mL at 760.0 mmHg.
Calculate the number of grams of sodium consumed in the
reaction.
g Na

6.4 cm (max) - 25 cm (min)

i think its 100

i hope this !

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.