Question

Naturally occurring element x exists in three isotopic forms: x-28 (27.977 amu, 92.23% abundance), x-29 (28.976 amu, 4.67% abundance), and x-30 (29.974 amu, 3.10% abundance). calculate the atomic weight of x.

Answer 1

To solve for the weighted average atomic weight of X, all we have to do is to calculate for the contribution of each isotope. The contribution of each isotope on the atomic weight of x is calculated by multiplying their respective atomic weights with the abundance, therefore:

X – 28 = 27.977 amu * (92.23 / 100)

X – 28 = 25.803 amu

 

X – 29 = 28.976 amu * (4.67 / 100)

X – 29 = 1.353 amu

 

X – 30 = 29.974 amu * (3.10 / 100)

X – 30 = 0.929 amu

 

Hence:

X = X – 28 + X – 29 + X – 30

X = 25.803 amu + 1.353 amu + 0.929 amu

X = 28.085 amu

Answer 2

The atomic weight of the naturally occurring element x that exists in three isotopic forms (x-28, x-29, and x-30) is 28.0856 amu.  

The atomic weight of x can be calculated by adding the atomic masses of the three isotopes with their respective abundance percentages, as follows:

$A = m_{x-28}\%_{x-28} + m_{x-29}\%_{x-29} + m_{x-30}\%_{x-30}$

$A = 27.977*92.23 \% + 28.976*4.67 \% + 29.974*3.10 \%$

To find the atomic weight we need to change the percent values to decimal ones (by dividing the percent value by 100):

$A = 27.977*\frac{92.23}{100} + 28.976*\frac{4.67}{100} + 29.974*\frac{3.10}{100}$

$A = 27.977*0.9223 + 28.976*0.0467 + 29.974*0.0310 = 28.0856$

Therefore, the atomic weight of x is 28.0856 amu.  

           

You can find more of the calculation of atomic weight here: https://brainly.com/question/13284739?referrer=searchResults            

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