Question

a hypothetical element E was discovered. it was found to exist in two isotopic form i.e 46E and 48E. the relative abundance of 46E is found to be 65% . what is the average atomic mass of element E

a) 47.0.
b)46.7
c)47.5
d)46.2

please help me out with proof ​

Answer 1

Answer:

Average atomic mass = F

1

M

1

+F

2

M

2

+...+F

n

M

n

Where F

1

,F

2

,...F

n

is the fraction representing the natural abundance of the isotope and M is the weight of the isotope.

Avg. At. Mass = (0.85×11)+(0.10×12)+(0.05×13)

= 9.35+1.2+0.65

Therefore, the average atomic mass = 11.2