calculate te atomic mass of nitrogen if the two common isotopes of nitrogen have masses of 14.003 amu (99.63% abundance) and 15.00 amu (0.37% abundance) Make the answer make sense and clear?

Answer 1

To calculate the atomic mass of nitrogen based on its isotopes, we can use the weighted average based on the abundance of each isotope.

We have two isotopes of nitrogen:

1. Nitrogen-14 (¹⁴N) with a mass of 14.003 amu and an abundance of 99.63%.
2. Nitrogen-15 (¹⁵N) with a mass of 15.00 amu and an abundance of 0.37%.

We will convert the percentages into decimal form for the calculation:

• 99.63% abundance for ¹⁴N becomes 0.9963.
• 0.37% abundance for ¹⁵N becomes 0.0037.

Next, we calculate the contribution of each isotope to the atomic mass of nitrogen:

1. Contribution from ¹⁴N: \[ 14.003 , \text{amu} \times 0.9963 = 13.95288109 , \text{amu} \]

2. Contribution from ¹⁵N: \[ 15.00 , \text{amu} \times 0.0037 = 0.0555 , \text{amu} \]

Now, we sum the contributions from both isotopes:

\[ \text{Atomic mass of nitrogen} = 13.95288109 , \text{amu} + 0.0555 , \text{amu} \approx 14.00838109 , \text{amu} \]

Finally, rounding this to three significant figures, we find:

\[ \text{Atomic mass of nitrogen} \approx 14.01 , \text{amu} \]

Thus, the atomic mass of nitrogen, considering its common isotopes and their abundances, is approximately 14.01 amu.