All living organisms on Earth contain carbon. If Carbon-12 amu mass = 12, makes up 98.89%, and Carbon-13, amu mass = 13, makes up the other 1.11%, what is the average atomic mass of carbon?
I'm a little confused how to go about this question. What does the information show me and how do I use it to get the answer.
2007-09-08 03:58:44 · 2 answers · asked by Average Joes 4 in Science & Mathematics ➔ Chemistry
12 * .9889 + 13 * .0111 = 12.0111
It tells you what percentages of C weights what... You need the average weight. So combining the weights with the percentages in the above manner gives the answer you need.
2007-09-08 04:07:51 · answer #1 · answered by Anonymous · 0⤊ 0⤋
add up the percent-mass of each;
Carbon 12: 12amu x 0.9889 = 11.8668
Carbon 13: 13amu x 0.011 = 0.143
Add 11.8668 + 0.143 = 12.0098
12.0098 is the average atomic mass (aam) of carbon
The information shows you the two different known ways carbon appears to us in nature, and how often each appears. We use that to form an average mass of all Carbon atoms.
12.0098 is the aam on most periodic tables under Carbon
2007-09-08 11:11:09 · answer #2 · answered by Doug 5 · 0⤊ 0⤋