Question

What is packing fraction of ${}_{26}F{{e}^{56}}$ ? (At. mass = 55.92066)

• A. $+\,14.167$
• B. $+\,73.90$
• C. $-14.167$
• D. $-\,73.90$

Answer 1

Answer: (C)

$-14.167$

Answer 2

We know that Packing fraction $=\frac{\text{Isotopic}\,\text{mass}-\,\text{mass}\,\text{number}}{\text{mass}\,\text{number}}\times {{10}^{4}}$ $=\frac{55.92066-56}{56}\times {{10}^{4}}$ $=-\frac{0.07934}{56}\times 10000=-\,14.167$