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Strontium consists of four isotopes with masses of 84 (abundance 0.50%), 86 (abundance of 9.9%), 87 (abundance of 7.0%), and 88 (abundance of 82.6%). What is the atomic mass of strontium?
87.71 amu (I am assuming degrees of significance here...) In order to determine the average of an element, we take the weighted average of all of the of that element....
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The atomic weight of a newly discovered element is 110.352 amu. It has two naturally occurring isotopes. One has a mass of 111.624 amu. The other has an isotopic mass of 109.75 amu. What is the percent abundance of the last isotope (109.75 amu)?
The idea here is that each isotope will contribute to the average of the element proportionally to their respective abundance. Now, the key to this problem lies in how you...
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The element copper has naturally occurring isotopes with mass numbers of 63 and 65. The relative abundance and atomic masses are 69.2% for a mass of 62.93 amu and 30.8% for a mass of 64.93 amu. What is the average atomic mass of copper?
$""^63Cu$ has $69.2%$ abundance. $""^65Cu$ has $30.8%$ abundance. So, the weighted average is $62.93xx69.2%$ $+$ $64.93xx30.8%$ $=$ $63.55$ $"amu"$. If we look at , copper metal (a mixture of isotopes...
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One isotope of bromine has an atomic mass of 78.92 amu and a relative abundance of 50.69%. The other major isotope of has an atomic mass of 80.92 amu and a relative abundance of 49.31%? What is the average atomic mass of bromine?
Multiply the atomic mass of each isotope times its percent abundance in decimal form. Add them together. $"Average atomic mass of Br"$$=$$(78.92xx0.5069)+(80.92xx0.49331)="79.92 u"$
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The atomic weight of a newly discovered e ement is 98.225 amu. It has two naturally occuring isotopes. One isotope has a mass of 96.780 amu. The second isotope has a percent abundance of 41.7%. What is the mass of the second isotope?
$M_r=(sum(M_ia))/a$, where: $M_r$ = relative attomic mass ($g$ $mol^-1$) $M_i$ = mass of each isotope ($g$ $mol^-1$) $a$ = abundance, either given as a percent or amount of $g$...
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The atomic weight of a newly discovered element is 10.600 amu. It has two naturally occurring isotopes. One has a mass of 10.000 amu
and a natural abundance of 70.000%. What
is the isotopic mass of the other isotope?
So, $10.600 (mass$ $units) = 70%xx10.000 + 30%xxM_2;$ where $M_2$ is the isoptopic mass of the other isotope. So solve for $M_2$! A priori would you expect $M_2$ to...
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An average sample of chlorine contains 75.77% chlorine-35, with an atomic mass of 34.969 amu (atomic mass units), and 24.23% chlorine-37, with an atomic mass of 36.966 amu. What is the average atomic mass of chlorine?
The weighted average is the sum of each individual nuclide, multiplied by its isotopic abundance. So, we simply do the arithmetic: $0.7577xx34.969+0.2423xx36.966 = ???$ amu Then look at to...
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What is the average atomic mass of an element if, out of 100 atoms, 5 have a mass of 176 amu, 19 have a mass of 177 amu, 27 have a mass of 178 amu, 14 have a mass of 179 amu, and 35 have a mass of 180 amu?
The $"Average Atomic Mass"$ of an element is defined as "the weighted average mass of all naturally-occurring (occasionally radioactive) of the element." (and hence the name "average") [1] Dividing the...
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2. The element copper has naturally occurring isotopes with mass numbers of 63 and 65. The relative abundance and atomic masses are 69.2% for a mass of 62.93 amu and 30.8% for a mass of 64.93 amu. How do you calculate the average atomic mass of copper?
And thus the $"weighted average"$ is: $(62.93xx69.2%+64.93xx30.8%)*"amu"$ $=$ $63.55$ $"amu"$
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The atomic weight of Ga is 69.72 amu. There are only two naturally occurring isotopes of gallium: $"^69Ga$ with a weight of 69.0 amu, and $"^71Ga$ with a weight of 71.0 amu. What is approximate natural abundance of the $"^71Ga$ isotope?
Let the percentage of the isotope $""^71Ga$ be $=x%$ Then, The percentage of the isotope $""^69Ga$ is $=(100-x)%$ We write the mass balance equation $100*69.72=x*71+(100-x)*69$ $6972=71x+6900-69x$ $2x=6972-6900=72$ $x=36$ Therefore, The...
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