Question

one compreeSCOTT DE VUOTTESUTICE Question Completion Status: Moving to another question will save this response. Question 7 Calculate the atomic mass of element "X", if it has 2 naturally occurring isotopes with the following masses and natural abundances: X-45 44.8776 amu 32.88% X-47 46 9443 amu 67.12% A) 46.26 amu B) 45.91 amu C) 46.34 amu D) 46.84 amu E) 44.99 amu A Moving to another question will save this response. $ 7 8 9 6 2 5 3 4. W E R Т. Y

Answer 1

Answer)

Given:

X - 45	44.8776 amu	32.88 %
x - 47	46.9443 amu	67.12 %

Now,

The average atomic mass of an element is the sum of masses of there isotopes multiplied by their abundance in nature.

So,

Average atomic mass = f₁m₁ + f₂m₂

Where,   

f₁ = fraction of X - 45 = 0.3288

m₁ = mass of X-45 = 44.8776 amu  

f₂ = fraction of X - 47 = 0.6712

m₂ = mass of X - 47 = 46.9443 amu

So,

Average atomic mass = (0.3288) * (44.8776) = (0.6712) * (46.9443)

Average atomic mass = 46.26

So, the average atomic mass of element X is 46.26 amu.