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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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Oxygen is composed of three isotopes 16/8 O (15.995 u), 17/8 O (16.999 u) and 18/8 O (17.999 u). One of these isotopes, 17/8 O, comprises of 0.037% of oxygen. What is the percentage abundance of the other two isotopes, using the average atomic mass of 15.9994 u.
The abundance of $""_8^16"O"$ is 99.762 %, and the abundance of $""_8^18"O"$ is 0.201 %. Assume you have 100 000 atoms of O. Then you have 37 atoms of $""_8^17"O"$...
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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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Vanadium has two naturally occurring isotopes, 50-V with an atomic mass of 49.9472 amu and 51-V with an atomic mass of 50.9440. The atomic weight of vanadium is 50.9415. What is the percent abundance of the vanadium isotopes?
The idea with that have two naturally occurring is that the percent abundances of those two must add up to give $100%$. In calculations, it is often easier to...
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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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Silver has two naturally occurring isotopes with the following isotopic masses 106.90509 and 108.9047. The average atomic mass of silver is 107.8682 amu. What is the fractional abundance of the lighter of the two isotopes?
We know that: $x_(1)106.9059 + x_(2)108.9047 = 107.8682$ $(i)$ $x_(1) + x_(2) = 1$ $(ii)$ We assume that silver has only the 2 , which for a first approximation...
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The element antimony has an atomic weight of 121.757 u and only two naturally occurring isotopes. One isotope has an abundance of 57.3% and an isotopic mass of 120.904 u. What is the mass of the other isotope?
The mass of antimony's second naturally occurring is $"122.902 u"$ The thing to know when doing isotope abundance problems is that the abundances of the two must add up to...
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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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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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Silver has two naturally occurring isotopes. Ag- 107 with a mass of 106.905 amu and a natural abundance of 51.84 % and Ag-109. How do you use the atomic mass of silver listed in the periodic table to determine the mass of Ag-109?
Using my (not very precise) periodic table, I get the mass of Ag as 107.87. This must be a combination of these two . So the % of the other...
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