Question

How to determine the abundance of each isotope

Answer 1

121*(abundance percentage of Sb-121)+123*(abundance percentage of Sb-123)=121.8 ?

Answer 2

(Atomic Mass of Antimony-121)(Percent Abundance of Antimony-121) + (Atomic Mass of Antimony-123)(Percent Abundance of Antimony-123) = 121.8

replace them as x and y

by percentage we know that
x+y = 1
so 1-x = y

Answer 3

(121)x + 123(1-x) = 121.8
then
121x + 123 - 123x = 121.8

solve for x
then use that value of x to solve for y

it is like solving wit linear equations right?

Answer 4

Yes, it's like solving with linear equations. Thanks :) !

Answer 5

So,
-2x+123=121.8
-2x=-123+121.8
-2x=-1.2

x=-1.2/-2
which makes x=0.6

that's for Sb121

if so, then x+y=1
0.6 +y =1
y=0.4

Answer 6

yes

Answer 7

estimated 60% and 40%
since your numbers are rounded off

Answer 8

lol, the element had two natural occurring isotopes, and i forgot to link those in sorry. No wonder you were confused.

Answer 9

I wasn't confused this was just common
they have their own amu's but for simplicity we go by the Element-isotope

Answer 10

so with appropriate amu's you can substitute with 121 and 123 :)
the same technique is used

Answer 11

Got it, thanks!!!!!! :)

Answer 12

make sure you follow significant figures

Answer 13

Yeah, my prof is soooo picky about them, but you need it for measurements. I can't escape that.