Question

I need Help!!

Nitrogen has two naturally occurring isotopes, N-14 and N-15. the atomic mass of nitrogen is 14.007 amu. which isotope is more abundant in nature? Explain

Answer 1

N 14 is most abundant, the atomic mass is 7 so the most abundant one must have 7 neutrons (14-7) while N 15 would have 8 neutrons

Answer 2

N-14 is most abundant..you can see it from atomic mass of nitrogen 14.007..its close to 14 rather that 15..N-14 is most abundant...
you can find its abundances by solving too...

Answer 3

14.007 amu = \(N^{14}_{mass}*\%abundance_{N^{14}}+N^{15}_{mass}*\%abundance_{N^{15}}\)

Their abundance have to equal to 100%, right?

\(\%abundance_{N^{14}}+\%abundance_{N^{15}}=1\)

\(1-\%abundance_{N^{14}}=\%abundance_{N^{15}}\)

substitute it back into the first equation:

14.007 amu = \(N^{14}_{mass}*\%abundance_{N^{14}}+N^{15}_{mass}*(1-\%abundance_{N^{14}})\)

solve: \(\%abundance_{N^{14}}=0.993=99.3 \%\)

\(\%abundance_{N^{15}}=1-0.993=0.07= 0.7\%\)