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Nitrogen (N) is made up of 99.632% 14N and 0.368% 15N. The atomic mass of 14N is 14.003 amu. The atomic mass of 15N is 15.000 amu. What is the average atomic mass of nitrogen?. . A. 14.0 amu. . B. 14.006 amu. . C. 15.00 amu. . D. 15.50 amu.

2 Answers

7 votes

Answer:

14.006 amu

Step-by-step explanation:

The other answer has a great explanation so I'm not gonna give any details. I just want to confirm this answer to be correct! :D Good luck on your test!

User Niatia
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8.5k points
1 vote
We calculate as follows:

We first change the percentages to mole fractions by moving the decimal two places to the left.

N-14 (14.003amu)(0.99632) = 13.9515amu

N-15 (15.000amu)(0.00368) = 0.0552amu

Total = 14.0067 amu -------> OPTION B


Hope this answers the question. Have a nice day.

User John Zablocki
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8.2k points