Two isotopes of copper are naturally occurring with ^63Cu at 69.09% (62.93 amu) and ^65Cu at 30.91% (64.93amu ). What is the atomic mass of copper?
2007-02-27 16:09:24 · 6 answers · asked by orange_crush_05 6 in Science & Mathematics ➔ Chemistry
Don't read too much into this, the answer is quite simple:
x = 0.6909*62.93amu + 0.3091*64.93amu
And that's it (I'll let you punch it in).
2007-02-27 16:18:08 · answer #1 · answered by Anonymous · 1⤊ 0⤋
Simply multiply the percentages by hte weight and divide by 100.
( 69.09 * 62.93 ) + ( 30.91 * 64.93 ) / 100, you answer will be in AMU.
Look at it this way; (Its the Candy Store Problem, again!)
You have 10,000 atoms of copper.
6,909 atoms weigh 62.93 amu each and 3,091 weigh 64.93 each.
What is the average weight of an atom of copper?
2007-02-28 00:21:22 · answer #2 · answered by RichardPaulHall 4 · 0⤊ 0⤋
take the mass of the 63 copper atom times 69.09% + the mass of the 65 copper atom times 30.91%
2007-02-28 00:19:55 · answer #3 · answered by walter_b_marvin 5 · 0⤊ 0⤋
Since atomic mass is the weighted average AMU of all isotopes.
(.6909 * 62.93) + (.3091 * 64.93) = 63.54 AMU
2007-02-28 00:20:16 · answer #4 · answered by nothereanymoreomgteh 4 · 0⤊ 0⤋
All u have to do is multiply 0.6909 by 62.93=43.47 and then multiply 0.3091 by 64.93=20.069 then u add 43.47+20.07=63.54. That is your final answer hope it helped. and good luck in chemistry I just took chem 1 last semester I hated it and so I know how u feel that is why I answered it. Good Luck!
2007-02-28 01:32:10 · answer #5 · answered by Navid D 1 · 0⤊ 0⤋
Did someone not do their homework?lol
2007-02-28 00:16:59 · answer #6 · answered by Shiloh 5 · 0⤊ 1⤋