Question

1. silicon has three naturally occurring isotope. apply your knowledge of calculating the average atomic to determine the average atomic mass of silicon.

Explanation:

Step1: Recall the formula for average atomic mass

The formula is $\sum_{i}(m_i\times p_i)$, where $m_i$ is the mass - number of the isotope and $p_i$ is the percentage abundance of the isotope (expressed as a decimal).

Step2: Convert percentages to decimals

$92.23\%=0.9223$, $4.67\% = 0.0467$, $3.10\%=0.0310$.

Step3: Calculate the contribution of each isotope

For the isotope with mass - number 28: $28\times0.9223 = 25.8244$.
For the isotope with mass - number 29: $29\times0.0467=1.3543$.
For the isotope with mass - number 30: $30\times0.0310 = 0.93$.

Step4: Sum up the contributions

$25.8244+1.3543 + 0.93=28.1087\approx28.11$.

Answer:

$28.11$