Question

1. calculate the atomic mass of boron using the isotopes listed below. you must show your work - to do this type in your formula set up. for your final answer label it clearly (for example: answer = 37.4amu). isotopes of boron: - boron - 10 mass(10.01amu) abundance(19%) - boron - 11 mass(11.01amu) abundance(81%)

Explanation:

Step1: Recall the formula for atomic mass

The formula for atomic mass ($A$) is $A=\sum_{i} (m_i\times p_i)$, where $m_i$ is the mass of the isotope and $p_i$ is its percent - abundance (expressed as a decimal).

Step2: Convert percent - abundances to decimals

For Boron - 10, the percent - abundance is 19%, so $p_{10}=0.19$. For Boron - 11, the percent - abundance is 81%, so $p_{11}=0.81$.

Step3: Calculate the contribution of each isotope to the atomic mass

The mass of Boron - 10 is $m_{10} = 10.01\ amu$, so its contribution is $m_{10}\times p_{10}=10.01\times0.19 = 1.9019\ amu$. The mass of Boron - 11 is $m_{11}=11.01\ amu$, so its contribution is $m_{11}\times p_{11}=11.01\times0.81 = 8.9181\ amu$.

Step4: Calculate the atomic mass of boron

$A=(10.01\times0.19)+(11.01\times0.81)=1.9019 + 8.9181=10.82\ amu$

Answer:

= 10.82amu