How many atoms are in 356.13 grams of sn

There are three atoms of Sn (Stannous or Tin) in 356.13 g of Sn.

One atom of Sn has the atomic mass (mₐ) of 118,71u which means:

356.13/118.71=3 atoms of Sn

The mass number (symbol A) also called atomic mass number or nucleon number is the total number of protons and neutrons in an atomic nucleus. It determines the atomic mass of atoms and it is in the periodic table.

i would say b

explanation:

but i think i would need more information than that

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.