If all of the scn- is complexed with fe3+ to form fencs2+ what is the molar concentration of fencs2+

number of moles of SCN⁻ = 0 .001 X 3 / 1000 = 3 X 10⁻⁶ moles    in the 25 ml of solution

2) SCN⁻ + Fe³⁺ ===> FeNCS²⁺

1 mole SCN⁻ produces 1 mole of FeNCS²⁺

Therefore moles of FeNCS²⁺ in 25 ml = 3 X 10⁻⁶

Molar Concentration of FeNCS²⁺ = (3 X10⁻⁶ )X 1000 / 25 = 1.2 X 10⁻⁴ Moles / liter

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.