there are two naturally occurring isotopes of the element zinc. the relative abundance and mass of each are as follow
64
30zn=48.89% 63.929 amu
66
30zn=27.81% 65.926
is it 0.4889(63.929)+027.81(65.926) divide by 2?
What else is in the naturally occuring zinc, the abundance of the two isotopes combined is only 76 percent (about) by adding 48.9+27.8 . Something else has to be there.
Dont divide by two, you will divide by 1.0 (the sum of the abundances, hopefully 100 precent or 1.0). But something is missing here.
To find the average atomic mass of zinc (Zn), also known as the atomic weight, you need to calculate the weighted average of the masses of its isotopes based on their relative abundance.
To do this, you can use the formula:
Average Atomic Mass = (Abundance₁ * Mass₁) + (Abundance₂ * Mass₂) / 100
First, convert the abundances to decimal form by dividing each abundance percentage by 100:
Abundance of 64Zn = 48.89% / 100 = 0.4889
Abundance of 66Zn = 27.81% / 100 = 0.2781
Next, plug in the values into the formula:
Average Atomic Mass = (0.4889 * 63.929 amu) + (0.2781 * 65.926 amu) / 2
Calculating the expression:
Average Atomic Mass = (31.2386841 amu) + (18.2885106 amu) / 2
Simplifying the equation:
Average Atomic Mass = 49.5271947 amu / 2
Finally, divide the result by 2 to get the average atomic mass of zinc:
Average Atomic Mass = 24.76359735 amu
Yes, you are on the right track. To calculate the average atomic mass of zinc, you need to multiply the relative abundance of each isotope by its respective mass, and then sum the values. Finally, divide the total value by 100 to obtain the average atomic mass.
Let's calculate it step by step:
1. Multiply the relative abundance of each isotope by its respective mass:
(48.89% * 63.929 amu) + (27.81% * 65.926 amu)
2. Add the values obtained:
(0.4889 * 63.929) + (0.2781 * 65.926)
3. Divide the total value by 100 to get the average atomic mass:
[(0.4889 * 63.929) + (0.2781 * 65.926)] / 100
By performing these calculations, you will find the average atomic mass of zinc.