What Is the Atomic Mass of Element A with Given Isotopes and Abundances?

AI Thread Summary
To find the atomic mass of element A, the isotopes and their abundances must be used in the weighted average formula. The isotopes provided are 86A with an atomic mass of 85.909 u and an abundance of 16.19%, 87A with an atomic mass of 86.908 u and an abundance of 7.00%, and 88A with an unknown abundance calculated as 76.81%. The equation for the atomic mass is (85.909 x 0.1619) + (86.908 x 0.07) + (87.906 x 0.7681). By plugging in these values, the atomic mass of element A can be determined for the periodic table.
CMATT
Messages
31
Reaction score
1

Homework Statement


Suppose the element A contains three isotopes, 86A (atomic mass 85.909 u, abundance 16.19%) 87A (atomic mass 86.908, abundance 7.00%) and 88A (atomic mass 87.906 u). What would be the atomic mass of A that would appear in the periodic table?

Homework Equations


(A1 x %A1) + (A2 x %A2) + (A3 x (1-(%1 +%2)) = answer

The Attempt at a Solution



16.19% + 7.00% = 23.19%

100% - 23.19% = 76.81% --> so that would be the 88A abundance % right?

then I'm confused from there. Please help
 
Physics news on Phys.org
CMATT said:
100% - 23.19% = 76.81% --> so that would be the 88A abundance % right?
Sure.
CMATT said:
then I'm confused from there. Please help
Just plug everything into the equation you have.
 
Thread 'Confusion regarding a chemical kinetics problem'

Thread 'Confusion regarding a chemical kinetics problem'

TL;DR Summary: cannot find out error in solution proposed. [![question with rate laws][1]][1] Now the rate law for the reaction (i.e reaction rate) can be written as: $$ R= k[N_2O_5] $$ my main question is, WHAT is this reaction equal to? what I mean here is, whether $$k[N_2O_5]= -d[N_2O_5]/dt$$ or is it $$k[N_2O_5]= -1/2 \frac{d}{dt} [N_2O_5] $$ ? The latter seems to be more apt, as the reaction rate must be -1/2 (disappearance rate of N2O5), which adheres to the stoichiometry of the...
View full post »

Thread 'Prove that evolution is constant (Provide at least two arguments to support your position)'

I don't get how to argue it. i can prove: evolution is the ability to adapt, whether it's progression or regression from some point of view, so if evolution is not constant then animal generations couldn`t stay alive for a big amount of time because when climate is changing this generations die. but they dont. so evolution is constant. but its not an argument, right? how to fing arguments when i only prove it.. analytically, i guess it called that (this is indirectly related to biology, im...
View full post »

Similar threads

Bromine Isotopes: Mass, Atomic Mass & Percent Abundance
Replies
2
Views
7K
Atomic Mass of Element X: Solving with John Dalton Ratios
Replies
13
Views
3K
Why wasn't fluorine used as a standard for atomic mass?
Replies
6
Views
3K
Chemistry - isotpic mass, atomic mass, mass number
Replies
1
Views
5K
How to Calculate Relative Atomic Mass Without Abundance Information?
Replies
1
Views
2K
What is the difference between amu and u in atomic mass units?
Replies
1
Views
7K
Percent composition of Silver (two naturally occurring isotopes)
Replies
1
Views
2K
Calculate % Natural Abundance of Carbon-13
Replies
2
Views
3K
Calculating Approximate Atomic Mass of Lead | Isotopes of Pb and Percent by Mass
Replies
29
Views
19K
Mass Spectrometry Homework: Relative Abundance of S-32 & S-34
Replies
1
Views
3K

Hot Threads

Recent Insights

Back
Top