Question

compute the average atomic mass for silicon: isotope percent abundance mass (amu) silicon - 28 91.22 27.977 silicon - 29 4.69 28.976 silicon - 30 3.09 29.974 compute the average atomic mass for silicon: 27.977 28.976 28.09 the average mass cannot be determined from provided information.

Explanation:

Step1: Convert percentages to decimals

$91.22\% = 0.9122$, $4.69\%=0.0469$, $3.09\% = 0.0309$

Step2: Multiply abundance by mass for each isotope

For silicon - 28: $0.9122\times27.977=25.4227894$
For silicon - 29: $0.0469\times28.976 = 1.3589744$
For silicon - 30: $0.0309\times29.974=0.9261966$

Step3: Sum the results

$25.4227894 + 1.3589744+0.9261966 = 27.7079604\approx28.09$

Answer:

28.09