Question

1. strontium consists of four isotopes with masses of 84 (abundance 0.50%), 86 (abundance of 9.9%), 87 (abundance of 7.0%), and 88 (abundance of 82.6%). calculate the atomic mass of strontium.

Explanation:

Step1: Convert abundances to decimals

$0.50\% = 0.005$, $9.9\%=0.099$, $7.0\% = 0.07$, $82.6\%=0.826$

Step2: Calculate the contribution of each isotope

For isotope with mass 84: $84\times0.005 = 0.42$
For isotope with mass 86: $86\times0.099 = 8.514$
For isotope with mass 87: $87\times0.07 = 6.09$
For isotope with mass 88: $88\times0.826 = 72.688$

Step3: Sum up the contributions

$0.42 + 8.514+6.09 + 72.688=87.712$

Answer:

$87.712$