Answer to Question #164035 in General Chemistry for Giavana Liberto

Question

can you identify an element just by the mass number alone? why or why not

Answer 1

No we can't identify the element just by the mass number alone.

We can't identify the element just by the mass number because mass number is not the characteristics of an element.

Mass number, A = Z + N

Z = number of proton inside the nuclei

N = number of nutron inside the nuclei

For a given value of mass number "A" there is a wide range solution of "Z" and "N" values .

E.g. for A = 13

Z = 6,N = 7, element: ¹³C₆ and Z = 7,N= 6, element: ¹³N₇

If "Z" value changes the element changed so we can't identify the element by just looking at the mass number "A".