Question

1. look at the isotope data below:

isotope mass (amu) abundance (%)
silver - 107 106.905 51.8%
silver - 109 108.905 48.2%
calculate the average atomic mass of silver. round to two decimal places.
which isotope contributes more to the average?

Explanation:

Step1: Convert percentages to decimals

$51.8\% = 0.518$, $48.2\%=0.482$

Step2: Calculate the weighted - mass contribution of Silver - 107

$106.905\times0.518 = 55.47679$

Step3: Calculate the weighted - mass contribution of Silver - 109

$108.905\times0.482 = 52.59221$

Step4: Calculate the average atomic mass

$55.47679 + 52.59221=108.07$

Step5: Determine the more - contributing isotope

Since the abundance of Silver - 107 ($51.8\%$) is greater than that of Silver - 109 ($48.2\%$), Silver - 107 contributes more to the average.

Answer:

The average atomic mass of silver is $108.07$ amu.
Silver - 107 contributes more to the average.