Question

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.

Answer 1

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.

Answer 2

Answer:

14.006 amu

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!