Question

The element nitrogen has an atomic weight of 14.0 and consists of two stable isotopes nitrogen-14 and nitrogen-15. The isotope nitrogen-14 has a mass of 14.0 amu and a percent natural abundance of 99.6 %. The isotope nitrogen-15 has a percent natural abundance of 0.370 %. What is the mass of nitrogen-15?

Answer 1

The mass of N-15 is 15 amu.

Chemical elements are represented using their symbols, their mass number and their proton numbers. The mass number of this isotope of nitrogen is shown next to the symbol. Regardless of the mass of the isotopes, their proton number is the same, which is 7.